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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:11:28 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:11:28 +0000 |
| commit | 94a0819fe3a0d679c3042a77bfe6a2afc505daea (patch) | |
| tree | 2b827afe6a05f3538db3f7803a88c4587fe85648 /library/core | |
| parent | Adding upstream version 1.64.0+dfsg1. (diff) | |
| download | rustc-94a0819fe3a0d679c3042a77bfe6a2afc505daea.tar.xz rustc-94a0819fe3a0d679c3042a77bfe6a2afc505daea.zip | |
Adding upstream version 1.66.0+dfsg1.upstream/1.66.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'library/core')
137 files changed, 6203 insertions, 2634 deletions
diff --git a/library/core/benches/iter.rs b/library/core/benches/iter.rs index 0abe20e4c..38887f29a 100644 --- a/library/core/benches/iter.rs +++ b/library/core/benches/iter.rs @@ -1,4 +1,6 @@ use core::iter::*; +use core::mem; +use core::num::Wrapping; use test::{black_box, Bencher}; #[bench] @@ -364,6 +366,13 @@ fn bench_partial_cmp(b: &mut Bencher) { } #[bench] +fn bench_chain_partial_cmp(b: &mut Bencher) { + b.iter(|| { + (0..50000).chain(50000..100000).map(black_box).partial_cmp((0..100000).map(black_box)) + }) +} + +#[bench] fn bench_lt(b: &mut Bencher) { b.iter(|| (0..100000).map(black_box).lt((0..100000).map(black_box))) } @@ -391,3 +400,21 @@ fn bench_trusted_random_access_adapters(b: &mut Bencher) { acc }) } + +/// Exercises the iter::Copied specialization for slice::Iter +#[bench] +fn bench_copied_array_chunks(b: &mut Bencher) { + let v = vec![1u8; 1024]; + + b.iter(|| { + black_box(&v) + .iter() + .copied() + .array_chunks::<{ mem::size_of::<u64>() }>() + .map(|ary| { + let d = u64::from_ne_bytes(ary); + Wrapping(d.rotate_left(7).wrapping_add(1)) + }) + .sum::<Wrapping<u64>>() + }) +} diff --git a/library/core/benches/lib.rs b/library/core/benches/lib.rs index a6c174d2f..1e462e3fc 100644 --- a/library/core/benches/lib.rs +++ b/library/core/benches/lib.rs @@ -4,6 +4,7 @@ #![feature(int_log)] #![feature(test)] #![feature(trusted_random_access)] +#![feature(iter_array_chunks)] extern crate test; diff --git a/library/core/benches/num/int_log/mod.rs b/library/core/benches/num/int_log/mod.rs index 19864d2d4..3c01e2998 100644 --- a/library/core/benches/num/int_log/mod.rs +++ b/library/core/benches/num/int_log/mod.rs @@ -9,7 +9,7 @@ macro_rules! int_log_bench { for n in 0..(<$t>::BITS / 8) { for i in 1..=(100 as $t) { let x = black_box(i << (n * 8)); - black_box(x.log10()); + black_box(x.ilog10()); } } }); @@ -27,7 +27,7 @@ macro_rules! int_log_bench { .collect(); bench.iter(|| { for x in &numbers { - black_box(black_box(x).log10()); + black_box(black_box(x).ilog10()); } }); } @@ -44,7 +44,7 @@ macro_rules! int_log_bench { .collect(); bench.iter(|| { for x in &numbers { - black_box(black_box(x).log10()); + black_box(black_box(x).ilog10()); } }); } diff --git a/library/core/src/alloc/global.rs b/library/core/src/alloc/global.rs index 887246c60..6756eecd0 100644 --- a/library/core/src/alloc/global.rs +++ b/library/core/src/alloc/global.rs @@ -74,7 +74,7 @@ use crate::ptr; /// { /// return null_mut(); /// }; -/// (self.arena.get() as *mut u8).add(allocated) +/// self.arena.get().cast::<u8>().add(allocated) /// } /// unsafe fn dealloc(&self, _ptr: *mut u8, _layout: Layout) {} /// } diff --git a/library/core/src/alloc/layout.rs b/library/core/src/alloc/layout.rs index 2f378836c..920e559cc 100644 --- a/library/core/src/alloc/layout.rs +++ b/library/core/src/alloc/layout.rs @@ -1,4 +1,11 @@ +// Seemingly inconsequential code changes to this file can lead to measurable +// performance impact on compilation times, due at least in part to the fact +// that the layout code gets called from many instantiations of the various +// collections, resulting in having to optimize down excess IR multiple times. +// Your performance intuition is useless. Run perf. + use crate::cmp; +use crate::error::Error; use crate::fmt; use crate::mem::{self, ValidAlign}; use crate::ptr::NonNull; @@ -52,16 +59,23 @@ impl Layout { /// * `align` must be a power of two, /// /// * `size`, when rounded up to the nearest multiple of `align`, - /// must not overflow (i.e., the rounded value must be less than - /// or equal to `usize::MAX`). + /// must not overflow isize (i.e., the rounded value must be + /// less than or equal to `isize::MAX`). #[stable(feature = "alloc_layout", since = "1.28.0")] #[rustc_const_stable(feature = "const_alloc_layout_size_align", since = "1.50.0")] #[inline] + #[rustc_allow_const_fn_unstable(ptr_alignment_type)] pub const fn from_size_align(size: usize, align: usize) -> Result<Self, LayoutError> { if !align.is_power_of_two() { return Err(LayoutError); } + // SAFETY: just checked that align is a power of two. + Layout::from_size_valid_align(size, unsafe { ValidAlign::new_unchecked(align) }) + } + + #[inline(always)] + const fn max_size_for_align(align: ValidAlign) -> usize { // (power-of-two implies align != 0.) // Rounded up size is: @@ -76,13 +90,18 @@ impl Layout { // // Above implies that checking for summation overflow is both // necessary and sufficient. - if size > usize::MAX - (align - 1) { + isize::MAX as usize - (align.as_usize() - 1) + } + + /// Internal helper constructor to skip revalidating alignment validity. + #[inline] + const fn from_size_valid_align(size: usize, align: ValidAlign) -> Result<Self, LayoutError> { + if size > Self::max_size_for_align(align) { return Err(LayoutError); } - // SAFETY: the conditions for `from_size_align_unchecked` have been - // checked above. - unsafe { Ok(Layout::from_size_align_unchecked(size, align)) } + // SAFETY: Layout::size invariants checked above. + Ok(Layout { size, align }) } /// Creates a layout, bypassing all checks. @@ -95,9 +114,10 @@ impl Layout { #[rustc_const_stable(feature = "const_alloc_layout_unchecked", since = "1.36.0")] #[must_use] #[inline] + #[rustc_allow_const_fn_unstable(ptr_alignment_type)] pub const unsafe fn from_size_align_unchecked(size: usize, align: usize) -> Self { - // SAFETY: the caller must ensure that `align` is a power of two. - Layout { size, align: unsafe { ValidAlign::new_unchecked(align) } } + // SAFETY: the caller is required to uphold the preconditions. + unsafe { Layout { size, align: ValidAlign::new_unchecked(align) } } } /// The minimum size in bytes for a memory block of this layout. @@ -115,8 +135,9 @@ impl Layout { #[must_use = "this returns the minimum alignment, \ without modifying the layout"] #[inline] + #[rustc_allow_const_fn_unstable(ptr_alignment_type)] pub const fn align(&self) -> usize { - self.align.as_nonzero().get() + self.align.as_usize() } /// Constructs a `Layout` suitable for holding a value of type `T`. @@ -126,10 +147,9 @@ impl Layout { #[inline] pub const fn new<T>() -> Self { let (size, align) = size_align::<T>(); - // SAFETY: the align is guaranteed by Rust to be a power of two and - // the size+align combo is guaranteed to fit in our address space. As a - // result use the unchecked constructor here to avoid inserting code - // that panics if it isn't optimized well enough. + // SAFETY: if the type is instantiated, rustc already ensures that its + // layout is valid. Use the unchecked constructor to avoid inserting a + // panicking codepath that needs to be optimized out. unsafe { Layout::from_size_align_unchecked(size, align) } } @@ -141,7 +161,6 @@ impl Layout { #[inline] pub fn for_value<T: ?Sized>(t: &T) -> Self { let (size, align) = (mem::size_of_val(t), mem::align_of_val(t)); - debug_assert!(Layout::from_size_align(size, align).is_ok()); // SAFETY: see rationale in `new` for why this is using the unsafe variant unsafe { Layout::from_size_align_unchecked(size, align) } } @@ -176,7 +195,6 @@ impl Layout { pub unsafe fn for_value_raw<T: ?Sized>(t: *const T) -> Self { // SAFETY: we pass along the prerequisites of these functions to the caller let (size, align) = unsafe { (mem::size_of_val_raw(t), mem::align_of_val_raw(t)) }; - debug_assert!(Layout::from_size_align(size, align).is_ok()); // SAFETY: see rationale in `new` for why this is using the unsafe variant unsafe { Layout::from_size_align_unchecked(size, align) } } @@ -276,12 +294,11 @@ impl Layout { let pad = self.padding_needed_for(self.align()); // This cannot overflow. Quoting from the invariant of Layout: // > `size`, when rounded up to the nearest multiple of `align`, - // > must not overflow (i.e., the rounded value must be less than - // > `usize::MAX`) + // > must not overflow isize (i.e., the rounded value must be + // > less than or equal to `isize::MAX`) let new_size = self.size() + pad; - // SAFETY: self.align is already known to be valid and new_size has been - // padded already. + // SAFETY: padded size is guaranteed to not exceed `isize::MAX`. unsafe { Layout::from_size_align_unchecked(new_size, self.align()) } } @@ -298,14 +315,13 @@ impl Layout { pub fn repeat(&self, n: usize) -> Result<(Self, usize), LayoutError> { // This cannot overflow. Quoting from the invariant of Layout: // > `size`, when rounded up to the nearest multiple of `align`, - // > must not overflow (i.e., the rounded value must be less than - // > `usize::MAX`) + // > must not overflow isize (i.e., the rounded value must be + // > less than or equal to `isize::MAX`) let padded_size = self.size() + self.padding_needed_for(self.align()); let alloc_size = padded_size.checked_mul(n).ok_or(LayoutError)?; - // SAFETY: self.align is already known to be valid and alloc_size has been - // padded already. - unsafe { Ok((Layout::from_size_align_unchecked(alloc_size, self.align()), padded_size)) } + // The safe constructor is called here to enforce the isize size limit. + Layout::from_size_valid_align(alloc_size, self.align).map(|layout| (layout, padded_size)) } /// Creates a layout describing the record for `self` followed by @@ -356,13 +372,14 @@ impl Layout { #[stable(feature = "alloc_layout_manipulation", since = "1.44.0")] #[inline] pub fn extend(&self, next: Self) -> Result<(Self, usize), LayoutError> { - let new_align = cmp::max(self.align(), next.align()); + let new_align = cmp::max(self.align, next.align); let pad = self.padding_needed_for(next.align()); let offset = self.size().checked_add(pad).ok_or(LayoutError)?; let new_size = offset.checked_add(next.size()).ok_or(LayoutError)?; - let layout = Layout::from_size_align(new_size, new_align)?; + // The safe constructor is called here to enforce the isize size limit. + let layout = Layout::from_size_valid_align(new_size, new_align)?; Ok((layout, offset)) } @@ -382,7 +399,8 @@ impl Layout { #[inline] pub fn repeat_packed(&self, n: usize) -> Result<Self, LayoutError> { let size = self.size().checked_mul(n).ok_or(LayoutError)?; - Layout::from_size_align(size, self.align()) + // The safe constructor is called here to enforce the isize size limit. + Layout::from_size_valid_align(size, self.align) } /// Creates a layout describing the record for `self` followed by @@ -395,26 +413,39 @@ impl Layout { #[inline] pub fn extend_packed(&self, next: Self) -> Result<Self, LayoutError> { let new_size = self.size().checked_add(next.size()).ok_or(LayoutError)?; - Layout::from_size_align(new_size, self.align()) + // The safe constructor is called here to enforce the isize size limit. + Layout::from_size_valid_align(new_size, self.align) } /// Creates a layout describing the record for a `[T; n]`. /// - /// On arithmetic overflow, returns `LayoutError`. + /// On arithmetic overflow or when the total size would exceed + /// `isize::MAX`, returns `LayoutError`. #[stable(feature = "alloc_layout_manipulation", since = "1.44.0")] #[inline] pub fn array<T>(n: usize) -> Result<Self, LayoutError> { - let array_size = mem::size_of::<T>().checked_mul(n).ok_or(LayoutError)?; - - // SAFETY: - // - Size: `array_size` cannot be too big because `size_of::<T>()` must - // be a multiple of `align_of::<T>()`. Therefore, `array_size` - // rounded up to the nearest multiple of `align_of::<T>()` is just - // `array_size`. And `array_size` cannot be too big because it was - // just checked by the `checked_mul()`. - // - Alignment: `align_of::<T>()` will always give an acceptable - // (non-zero, power of two) alignment. - Ok(unsafe { Layout::from_size_align_unchecked(array_size, mem::align_of::<T>()) }) + // Reduce the amount of code we need to monomorphize per `T`. + return inner(mem::size_of::<T>(), ValidAlign::of::<T>(), n); + + #[inline] + fn inner(element_size: usize, align: ValidAlign, n: usize) -> Result<Layout, LayoutError> { + // We need to check two things about the size: + // - That the total size won't overflow a `usize`, and + // - That the total size still fits in an `isize`. + // By using division we can check them both with a single threshold. + // That'd usually be a bad idea, but thankfully here the element size + // and alignment are constants, so the compiler will fold all of it. + if element_size != 0 && n > Layout::max_size_for_align(align) / element_size { + return Err(LayoutError); + } + + let array_size = element_size * n; + + // SAFETY: We just checked above that the `array_size` will not + // exceed `isize::MAX` even when rounded up to the alignment. + // And `ValidAlign` guarantees it's a power of two. + unsafe { Ok(Layout::from_size_align_unchecked(array_size, align.as_usize())) } + } } } @@ -434,6 +465,9 @@ pub type LayoutErr = LayoutError; #[derive(Clone, PartialEq, Eq, Debug)] pub struct LayoutError; +#[stable(feature = "alloc_layout", since = "1.28.0")] +impl Error for LayoutError {} + // (we need this for downstream impl of trait Error) #[stable(feature = "alloc_layout", since = "1.28.0")] impl fmt::Display for LayoutError { diff --git a/library/core/src/alloc/mod.rs b/library/core/src/alloc/mod.rs index 6cc6e359e..a4bf6a853 100644 --- a/library/core/src/alloc/mod.rs +++ b/library/core/src/alloc/mod.rs @@ -21,6 +21,7 @@ pub use self::layout::LayoutErr; #[stable(feature = "alloc_layout_error", since = "1.50.0")] pub use self::layout::LayoutError; +use crate::error::Error; use crate::fmt; use crate::ptr::{self, NonNull}; @@ -32,6 +33,13 @@ use crate::ptr::{self, NonNull}; #[derive(Copy, Clone, PartialEq, Eq, Debug)] pub struct AllocError; +#[unstable( + feature = "allocator_api", + reason = "the precise API and guarantees it provides may be tweaked.", + issue = "32838" +)] +impl Error for AllocError {} + // (we need this for downstream impl of trait Error) #[unstable(feature = "allocator_api", issue = "32838")] impl fmt::Display for AllocError { @@ -97,6 +105,7 @@ impl fmt::Display for AllocError { /// /// [*currently allocated*]: #currently-allocated-memory #[unstable(feature = "allocator_api", issue = "32838")] +#[const_trait] pub unsafe trait Allocator { /// Attempts to allocate a block of memory. /// diff --git a/library/core/src/any.rs b/library/core/src/any.rs index f20c497a1..1a379ecc1 100644 --- a/library/core/src/any.rs +++ b/library/core/src/any.rs @@ -1,7 +1,4 @@ -//! This module contains the `Any` trait, which enables dynamic typing -//! of any `'static` type through runtime reflection. It also contains the -//! `Provider` trait and accompanying API, which enable trait objects to provide -//! data based on typed requests, an alternate form of runtime reflection. +//! Utilities for dynamic typing or type reflection. //! //! # `Any` and `TypeId` //! @@ -799,7 +796,7 @@ pub trait Provider { /// impl Provider for SomeConcreteType { /// fn provide<'a>(&'a self, demand: &mut Demand<'a>) { /// demand.provide_ref::<str>(&self.field) - /// .provide_value::<i32>(|| self.num_field); + /// .provide_value::<i32>(self.num_field); /// } /// } /// ``` @@ -884,28 +881,55 @@ impl<'a> Demand<'a> { /// /// # Examples /// + /// Provides an `u8`. + /// + /// ```rust + /// #![feature(provide_any)] + /// + /// use std::any::{Provider, Demand}; + /// # struct SomeConcreteType { field: u8 } + /// + /// impl Provider for SomeConcreteType { + /// fn provide<'a>(&'a self, demand: &mut Demand<'a>) { + /// demand.provide_value::<u8>(self.field); + /// } + /// } + /// ``` + #[unstable(feature = "provide_any", issue = "96024")] + pub fn provide_value<T>(&mut self, value: T) -> &mut Self + where + T: 'static, + { + self.provide::<tags::Value<T>>(value) + } + + /// Provide a value or other type with only static lifetimes computed using a closure. + /// + /// # Examples + /// /// Provides a `String` by cloning. /// /// ```rust - /// # #![feature(provide_any)] + /// #![feature(provide_any)] + /// /// use std::any::{Provider, Demand}; /// # struct SomeConcreteType { field: String } /// /// impl Provider for SomeConcreteType { /// fn provide<'a>(&'a self, demand: &mut Demand<'a>) { - /// demand.provide_value::<String>(|| self.field.clone()); + /// demand.provide_value_with::<String>(|| self.field.clone()); /// } /// } /// ``` #[unstable(feature = "provide_any", issue = "96024")] - pub fn provide_value<T>(&mut self, fulfil: impl FnOnce() -> T) -> &mut Self + pub fn provide_value_with<T>(&mut self, fulfil: impl FnOnce() -> T) -> &mut Self where T: 'static, { self.provide_with::<tags::Value<T>>(fulfil) } - /// Provide a reference, note that the referee type must be bounded by `'static`, + /// Provide a reference. The referee type must be bounded by `'static`, /// but may be unsized. /// /// # Examples @@ -913,7 +937,8 @@ impl<'a> Demand<'a> { /// Provides a reference to a field as a `&str`. /// /// ```rust - /// # #![feature(provide_any)] + /// #![feature(provide_any)] + /// /// use std::any::{Provider, Demand}; /// # struct SomeConcreteType { field: String } /// @@ -928,6 +953,40 @@ impl<'a> Demand<'a> { self.provide::<tags::Ref<tags::MaybeSizedValue<T>>>(value) } + /// Provide a reference computed using a closure. The referee type + /// must be bounded by `'static`, but may be unsized. + /// + /// # Examples + /// + /// Provides a reference to a field as a `&str`. + /// + /// ```rust + /// #![feature(provide_any)] + /// + /// use std::any::{Provider, Demand}; + /// # struct SomeConcreteType { business: String, party: String } + /// # fn today_is_a_weekday() -> bool { true } + /// + /// impl Provider for SomeConcreteType { + /// fn provide<'a>(&'a self, demand: &mut Demand<'a>) { + /// demand.provide_ref_with::<str>(|| { + /// if today_is_a_weekday() { + /// &self.business + /// } else { + /// &self.party + /// } + /// }); + /// } + /// } + /// ``` + #[unstable(feature = "provide_any", issue = "96024")] + pub fn provide_ref_with<T: ?Sized + 'static>( + &mut self, + fulfil: impl FnOnce() -> &'a T, + ) -> &mut Self { + self.provide_with::<tags::Ref<tags::MaybeSizedValue<T>>>(fulfil) + } + /// Provide a value with the given `Type` tag. fn provide<I>(&mut self, value: I::Reified) -> &mut Self where @@ -949,6 +1008,156 @@ impl<'a> Demand<'a> { } self } + + /// Check if the `Demand` would be satisfied if provided with a + /// value of the specified type. If the type does not match or has + /// already been provided, returns false. + /// + /// # Examples + /// + /// Check if an `u8` still needs to be provided and then provides + /// it. + /// + /// ```rust + /// #![feature(provide_any)] + /// + /// use std::any::{Provider, Demand}; + /// + /// struct Parent(Option<u8>); + /// + /// impl Provider for Parent { + /// fn provide<'a>(&'a self, demand: &mut Demand<'a>) { + /// if let Some(v) = self.0 { + /// demand.provide_value::<u8>(v); + /// } + /// } + /// } + /// + /// struct Child { + /// parent: Parent, + /// } + /// + /// impl Child { + /// // Pretend that this takes a lot of resources to evaluate. + /// fn an_expensive_computation(&self) -> Option<u8> { + /// Some(99) + /// } + /// } + /// + /// impl Provider for Child { + /// fn provide<'a>(&'a self, demand: &mut Demand<'a>) { + /// // In general, we don't know if this call will provide + /// // an `u8` value or not... + /// self.parent.provide(demand); + /// + /// // ...so we check to see if the `u8` is needed before + /// // we run our expensive computation. + /// if demand.would_be_satisfied_by_value_of::<u8>() { + /// if let Some(v) = self.an_expensive_computation() { + /// demand.provide_value::<u8>(v); + /// } + /// } + /// + /// // The demand will be satisfied now, regardless of if + /// // the parent provided the value or we did. + /// assert!(!demand.would_be_satisfied_by_value_of::<u8>()); + /// } + /// } + /// + /// let parent = Parent(Some(42)); + /// let child = Child { parent }; + /// assert_eq!(Some(42), std::any::request_value::<u8>(&child)); + /// + /// let parent = Parent(None); + /// let child = Child { parent }; + /// assert_eq!(Some(99), std::any::request_value::<u8>(&child)); + /// ``` + #[unstable(feature = "provide_any", issue = "96024")] + pub fn would_be_satisfied_by_value_of<T>(&self) -> bool + where + T: 'static, + { + self.would_be_satisfied_by::<tags::Value<T>>() + } + + /// Check if the `Demand` would be satisfied if provided with a + /// reference to a value of the specified type. If the type does + /// not match or has already been provided, returns false. + /// + /// # Examples + /// + /// Check if a `&str` still needs to be provided and then provides + /// it. + /// + /// ```rust + /// #![feature(provide_any)] + /// + /// use std::any::{Provider, Demand}; + /// + /// struct Parent(Option<String>); + /// + /// impl Provider for Parent { + /// fn provide<'a>(&'a self, demand: &mut Demand<'a>) { + /// if let Some(v) = &self.0 { + /// demand.provide_ref::<str>(v); + /// } + /// } + /// } + /// + /// struct Child { + /// parent: Parent, + /// name: String, + /// } + /// + /// impl Child { + /// // Pretend that this takes a lot of resources to evaluate. + /// fn an_expensive_computation(&self) -> Option<&str> { + /// Some(&self.name) + /// } + /// } + /// + /// impl Provider for Child { + /// fn provide<'a>(&'a self, demand: &mut Demand<'a>) { + /// // In general, we don't know if this call will provide + /// // a `str` reference or not... + /// self.parent.provide(demand); + /// + /// // ...so we check to see if the `&str` is needed before + /// // we run our expensive computation. + /// if demand.would_be_satisfied_by_ref_of::<str>() { + /// if let Some(v) = self.an_expensive_computation() { + /// demand.provide_ref::<str>(v); + /// } + /// } + /// + /// // The demand will be satisfied now, regardless of if + /// // the parent provided the reference or we did. + /// assert!(!demand.would_be_satisfied_by_ref_of::<str>()); + /// } + /// } + /// + /// let parent = Parent(Some("parent".into())); + /// let child = Child { parent, name: "child".into() }; + /// assert_eq!(Some("parent"), std::any::request_ref::<str>(&child)); + /// + /// let parent = Parent(None); + /// let child = Child { parent, name: "child".into() }; + /// assert_eq!(Some("child"), std::any::request_ref::<str>(&child)); + /// ``` + #[unstable(feature = "provide_any", issue = "96024")] + pub fn would_be_satisfied_by_ref_of<T>(&self) -> bool + where + T: ?Sized + 'static, + { + self.would_be_satisfied_by::<tags::Ref<tags::MaybeSizedValue<T>>>() + } + + fn would_be_satisfied_by<I>(&self) -> bool + where + I: tags::Type<'a>, + { + matches!(self.0.downcast::<I>(), Some(TaggedOption(None))) + } } #[unstable(feature = "provide_any", issue = "96024")] @@ -1053,6 +1262,21 @@ impl<'a> dyn Erased<'a> + 'a { /// Returns some reference to the dynamic value if it is tagged with `I`, /// or `None` otherwise. #[inline] + fn downcast<I>(&self) -> Option<&TaggedOption<'a, I>> + where + I: tags::Type<'a>, + { + if self.tag_id() == TypeId::of::<I>() { + // SAFETY: Just checked whether we're pointing to an I. + Some(unsafe { &*(self as *const Self).cast::<TaggedOption<'a, I>>() }) + } else { + None + } + } + + /// Returns some mutable reference to the dynamic value if it is tagged with `I`, + /// or `None` otherwise. + #[inline] fn downcast_mut<I>(&mut self) -> Option<&mut TaggedOption<'a, I>> where I: tags::Type<'a>, diff --git a/library/core/src/array/equality.rs b/library/core/src/array/equality.rs index 33f7f494e..b2c895f88 100644 --- a/library/core/src/array/equality.rs +++ b/library/core/src/array/equality.rs @@ -173,13 +173,14 @@ macro_rules! is_raw_eq_comparable { )+}; } -// SAFETY: All the ordinary integer types allow all bit patterns as distinct values +// SAFETY: All the ordinary integer types have no padding, and are not pointers. is_raw_eq_comparable!(u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize); -// SAFETY: bool and char have *niches*, but no *padding*, so this is sound +// SAFETY: bool and char have *niches*, but no *padding* (and these are not pointer types), so this +// is sound is_raw_eq_comparable!(bool, char); -// SAFETY: Similarly, the non-zero types have a niche, but no undef, +// SAFETY: Similarly, the non-zero types have a niche, but no undef and no pointers, // and they compare like their underlying numeric type. is_raw_eq_comparable!( NonZeroU8, diff --git a/library/core/src/array/iter.rs b/library/core/src/array/iter.rs index f4885ed9f..b91c63018 100644 --- a/library/core/src/array/iter.rs +++ b/library/core/src/array/iter.rs @@ -1,10 +1,10 @@ //! Defines the `IntoIter` owned iterator for arrays. use crate::{ - cmp, fmt, + fmt, iter::{self, ExactSizeIterator, FusedIterator, TrustedLen}, mem::{self, MaybeUninit}, - ops::Range, + ops::{IndexRange, Range}, ptr, }; @@ -29,9 +29,10 @@ pub struct IntoIter<T, const N: usize> { /// The elements in `data` that have not been yielded yet. /// /// Invariants: - /// - `alive.start <= alive.end` /// - `alive.end <= N` - alive: Range<usize>, + /// + /// (And the `IndexRange` type requires `alive.start <= alive.end`.) + alive: IndexRange, } // Note: the `#[rustc_skip_array_during_method_dispatch]` on `trait IntoIterator` @@ -69,7 +70,7 @@ impl<T, const N: usize> IntoIterator for [T; N] { // Until then, we can use `mem::transmute_copy` to create a bitwise copy // as a different type, then forget `array` so that it is not dropped. unsafe { - let iter = IntoIter { data: mem::transmute_copy(&self), alive: 0..N }; + let iter = IntoIter { data: mem::transmute_copy(&self), alive: IndexRange::zero_to(N) }; mem::forget(self); iter } @@ -103,8 +104,7 @@ impl<T, const N: usize> IntoIter<T, N> { /// /// ``` /// #![feature(array_into_iter_constructors)] - /// - /// #![feature(maybe_uninit_array_assume_init)] + /// #![feature(maybe_uninit_uninit_array_transpose)] /// #![feature(maybe_uninit_uninit_array)] /// use std::array::IntoIter; /// use std::mem::MaybeUninit; @@ -133,7 +133,7 @@ impl<T, const N: usize> IntoIter<T, N> { /// } /// /// // SAFETY: We've initialized all N items - /// unsafe { Ok(MaybeUninit::array_assume_init(buffer)) } + /// unsafe { Ok(buffer.transpose().assume_init()) } /// } /// /// let r: [_; 4] = next_chunk(&mut (10..16)).unwrap(); @@ -147,7 +147,9 @@ impl<T, const N: usize> IntoIter<T, N> { buffer: [MaybeUninit<T>; N], initialized: Range<usize>, ) -> Self { - Self { data: buffer, alive: initialized } + // SAFETY: one of our safety conditions is that the range is canonical. + let alive = unsafe { IndexRange::new_unchecked(initialized.start, initialized.end) }; + Self { data: buffer, alive } } /// Creates an iterator over `T` which returns no elements. @@ -283,16 +285,11 @@ impl<T, const N: usize> Iterator for IntoIter<T, N> { } fn advance_by(&mut self, n: usize) -> Result<(), usize> { - let len = self.len(); - - // The number of elements to drop. Always in-bounds by construction. - let delta = cmp::min(n, len); + let original_len = self.len(); - let range_to_drop = self.alive.start..(self.alive.start + delta); - - // Moving the start marks them as conceptually "dropped", so if anything - // goes bad then our drop impl won't double-free them. - self.alive.start += delta; + // This also moves the start, which marks them as conceptually "dropped", + // so if anything goes bad then our drop impl won't double-free them. + let range_to_drop = self.alive.take_prefix(n); // SAFETY: These elements are currently initialized, so it's fine to drop them. unsafe { @@ -300,7 +297,7 @@ impl<T, const N: usize> Iterator for IntoIter<T, N> { ptr::drop_in_place(MaybeUninit::slice_assume_init_mut(slice)); } - if n > len { Err(len) } else { Ok(()) } + if n > original_len { Err(original_len) } else { Ok(()) } } } @@ -338,16 +335,11 @@ impl<T, const N: usize> DoubleEndedIterator for IntoIter<T, N> { } fn advance_back_by(&mut self, n: usize) -> Result<(), usize> { - let len = self.len(); - - // The number of elements to drop. Always in-bounds by construction. - let delta = cmp::min(n, len); - - let range_to_drop = (self.alive.end - delta)..self.alive.end; + let original_len = self.len(); - // Moving the end marks them as conceptually "dropped", so if anything - // goes bad then our drop impl won't double-free them. - self.alive.end -= delta; + // This also moves the end, which marks them as conceptually "dropped", + // so if anything goes bad then our drop impl won't double-free them. + let range_to_drop = self.alive.take_suffix(n); // SAFETY: These elements are currently initialized, so it's fine to drop them. unsafe { @@ -355,7 +347,7 @@ impl<T, const N: usize> DoubleEndedIterator for IntoIter<T, N> { ptr::drop_in_place(MaybeUninit::slice_assume_init_mut(slice)); } - if n > len { Err(len) } else { Ok(()) } + if n > original_len { Err(original_len) } else { Ok(()) } } } @@ -372,9 +364,7 @@ impl<T, const N: usize> Drop for IntoIter<T, N> { #[stable(feature = "array_value_iter_impls", since = "1.40.0")] impl<T, const N: usize> ExactSizeIterator for IntoIter<T, N> { fn len(&self) -> usize { - // Will never underflow due to the invariant `alive.start <= - // alive.end`. - self.alive.end - self.alive.start + self.alive.len() } fn is_empty(&self) -> bool { self.alive.is_empty() @@ -396,14 +386,15 @@ impl<T: Clone, const N: usize> Clone for IntoIter<T, N> { fn clone(&self) -> Self { // Note, we don't really need to match the exact same alive range, so // we can just clone into offset 0 regardless of where `self` is. - let mut new = Self { data: MaybeUninit::uninit_array(), alive: 0..0 }; + let mut new = Self { data: MaybeUninit::uninit_array(), alive: IndexRange::zero_to(0) }; // Clone all alive elements. for (src, dst) in iter::zip(self.as_slice(), &mut new.data) { // Write a clone into the new array, then update its alive range. // If cloning panics, we'll correctly drop the previous items. dst.write(src.clone()); - new.alive.end += 1; + // This addition cannot overflow as we're iterating a slice + new.alive = IndexRange::zero_to(new.alive.end() + 1); } new diff --git a/library/core/src/array/mod.rs b/library/core/src/array/mod.rs index c9823a136..eae0e1c76 100644 --- a/library/core/src/array/mod.rs +++ b/library/core/src/array/mod.rs @@ -1,4 +1,4 @@ -//! Helper functions and types for fixed-length arrays. +//! Utilities for the array primitive type. //! //! *[See also the array primitive type](array).* @@ -7,6 +7,7 @@ use crate::borrow::{Borrow, BorrowMut}; use crate::cmp::Ordering; use crate::convert::{Infallible, TryFrom}; +use crate::error::Error; use crate::fmt; use crate::hash::{self, Hash}; use crate::iter::TrustedLen; @@ -31,6 +32,10 @@ pub use iter::IntoIter; /// # Example /// /// ```rust +/// // type inference is helping us here, the way `from_fn` knows how many +/// // elements to produce is the length of array down there: only arrays of +/// // equal lengths can be compared, so the const generic parameter `N` is +/// // inferred to be 5, thus creating array of 5 elements. /// let array = core::array::from_fn(|i| i); /// assert_eq!(array, [0, 1, 2, 3, 4]); /// ``` @@ -119,6 +124,14 @@ impl fmt::Display for TryFromSliceError { } } +#[stable(feature = "try_from", since = "1.34.0")] +impl Error for TryFromSliceError { + #[allow(deprecated)] + fn description(&self) -> &str { + self.__description() + } +} + impl TryFromSliceError { #[unstable( feature = "array_error_internals", @@ -173,6 +186,18 @@ impl<T, const N: usize> const BorrowMut<[T]> for [T; N] { } } +/// Tries to create an array `[T; N]` by copying from a slice `&[T]`. Succeeds if +/// `slice.len() == N`. +/// +/// ``` +/// let bytes: [u8; 3] = [1, 0, 2]; +/// +/// let bytes_head: [u8; 2] = <[u8; 2]>::try_from(&bytes[0..2]).unwrap(); +/// assert_eq!(1, u16::from_le_bytes(bytes_head)); +/// +/// let bytes_tail: [u8; 2] = bytes[1..3].try_into().unwrap(); +/// assert_eq!(512, u16::from_le_bytes(bytes_tail)); +/// ``` #[stable(feature = "try_from", since = "1.34.0")] impl<T, const N: usize> TryFrom<&[T]> for [T; N] where @@ -185,6 +210,18 @@ where } } +/// Tries to create an array `[T; N]` by copying from a mutable slice `&mut [T]`. +/// Succeeds if `slice.len() == N`. +/// +/// ``` +/// let mut bytes: [u8; 3] = [1, 0, 2]; +/// +/// let bytes_head: [u8; 2] = <[u8; 2]>::try_from(&mut bytes[0..2]).unwrap(); +/// assert_eq!(1, u16::from_le_bytes(bytes_head)); +/// +/// let bytes_tail: [u8; 2] = (&mut bytes[1..3]).try_into().unwrap(); +/// assert_eq!(512, u16::from_le_bytes(bytes_tail)); +/// ``` #[stable(feature = "try_from_mut_slice_to_array", since = "1.59.0")] impl<T, const N: usize> TryFrom<&mut [T]> for [T; N] where @@ -197,6 +234,18 @@ where } } +/// Tries to create an array ref `&[T; N]` from a slice ref `&[T]`. Succeeds if +/// `slice.len() == N`. +/// +/// ``` +/// let bytes: [u8; 3] = [1, 0, 2]; +/// +/// let bytes_head: &[u8; 2] = <&[u8; 2]>::try_from(&bytes[0..2]).unwrap(); +/// assert_eq!(1, u16::from_le_bytes(*bytes_head)); +/// +/// let bytes_tail: &[u8; 2] = bytes[1..3].try_into().unwrap(); +/// assert_eq!(512, u16::from_le_bytes(*bytes_tail)); +/// ``` #[stable(feature = "try_from", since = "1.34.0")] impl<'a, T, const N: usize> TryFrom<&'a [T]> for &'a [T; N] { type Error = TryFromSliceError; @@ -212,6 +261,18 @@ impl<'a, T, const N: usize> TryFrom<&'a [T]> for &'a [T; N] { } } +/// Tries to create a mutable array ref `&mut [T; N]` from a mutable slice ref +/// `&mut [T]`. Succeeds if `slice.len() == N`. +/// +/// ``` +/// let mut bytes: [u8; 3] = [1, 0, 2]; +/// +/// let bytes_head: &mut [u8; 2] = <&mut [u8; 2]>::try_from(&mut bytes[0..2]).unwrap(); +/// assert_eq!(1, u16::from_le_bytes(*bytes_head)); +/// +/// let bytes_tail: &mut [u8; 2] = (&mut bytes[1..3]).try_into().unwrap(); +/// assert_eq!(512, u16::from_le_bytes(*bytes_tail)); +/// ``` #[stable(feature = "try_from", since = "1.34.0")] impl<'a, T, const N: usize> TryFrom<&'a mut [T]> for &'a mut [T; N] { type Error = TryFromSliceError; @@ -375,7 +436,8 @@ impl<T: Copy> SpecArrayClone for T { macro_rules! array_impl_default { {$n:expr, $t:ident $($ts:ident)*} => { #[stable(since = "1.4.0", feature = "array_default")] - impl<T> Default for [T; $n] where T: Default { + #[rustc_const_unstable(feature = "const_default_impls", issue = "87864")] + impl<T> const Default for [T; $n] where T: ~const Default { fn default() -> [T; $n] { [$t::default(), $($ts::default()),*] } @@ -854,7 +916,7 @@ where mem::forget(guard); // SAFETY: All elements of the array were populated in the loop above. - let output = unsafe { MaybeUninit::array_assume_init(array) }; + let output = unsafe { array.transpose().assume_init() }; Ok(Try::from_output(output)) } diff --git a/library/core/src/bool.rs b/library/core/src/bool.rs index f7a8aa0d9..db1c505ba 100644 --- a/library/core/src/bool.rs +++ b/library/core/src/bool.rs @@ -6,12 +6,30 @@ impl bool { /// Returns `Some(t)` if the `bool` is [`true`](../std/keyword.true.html), /// or `None` otherwise. /// + /// Arguments passed to `then_some` are eagerly evaluated; if you are + /// passing the result of a function call, it is recommended to use + /// [`then`], which is lazily evaluated. + /// + /// [`then`]: bool::then + /// /// # Examples /// /// ``` /// assert_eq!(false.then_some(0), None); /// assert_eq!(true.then_some(0), Some(0)); /// ``` + /// + /// ``` + /// let mut a = 0; + /// let mut function_with_side_effects = || { a += 1; }; + /// + /// true.then_some(function_with_side_effects()); + /// false.then_some(function_with_side_effects()); + /// + /// // `a` is incremented twice because the value passed to `then_some` is + /// // evaluated eagerly. + /// assert_eq!(a, 2); + /// ``` #[stable(feature = "bool_to_option", since = "1.62.0")] #[rustc_const_unstable(feature = "const_bool_to_option", issue = "91917")] #[inline] @@ -31,6 +49,17 @@ impl bool { /// assert_eq!(false.then(|| 0), None); /// assert_eq!(true.then(|| 0), Some(0)); /// ``` + /// + /// ``` + /// let mut a = 0; + /// + /// true.then(|| { a += 1; }); + /// false.then(|| { a += 1; }); + /// + /// // `a` is incremented once because the closure is evaluated lazily by + /// // `then`. + /// assert_eq!(a, 1); + /// ``` #[stable(feature = "lazy_bool_to_option", since = "1.50.0")] #[rustc_const_unstable(feature = "const_bool_to_option", issue = "91917")] #[inline] diff --git a/library/core/src/borrow.rs b/library/core/src/borrow.rs index 58eabecf3..fdd56cb4e 100644 --- a/library/core/src/borrow.rs +++ b/library/core/src/borrow.rs @@ -1,4 +1,4 @@ -//! A module for working with borrowed data. +//! Utilities for working with borrowed data. #![stable(feature = "rust1", since = "1.0.0")] @@ -154,6 +154,7 @@ /// [`String`]: ../../std/string/struct.String.html #[stable(feature = "rust1", since = "1.0.0")] #[rustc_diagnostic_item = "Borrow"] +#[const_trait] pub trait Borrow<Borrowed: ?Sized> { /// Immutably borrows from an owned value. /// @@ -184,6 +185,7 @@ pub trait Borrow<Borrowed: ?Sized> { /// an underlying type by providing a mutable reference. See [`Borrow<T>`] /// for more information on borrowing as another type. #[stable(feature = "rust1", since = "1.0.0")] +#[const_trait] pub trait BorrowMut<Borrowed: ?Sized>: Borrow<Borrowed> { /// Mutably borrows from an owned value. /// diff --git a/library/core/src/cell.rs b/library/core/src/cell.rs index fb4454c94..7bf32cb0d 100644 --- a/library/core/src/cell.rs +++ b/library/core/src/cell.rs @@ -405,6 +405,7 @@ impl<T> Cell<T> { /// assert_eq!(cell.replace(10), 5); /// assert_eq!(cell.get(), 10); /// ``` + #[inline] #[stable(feature = "move_cell", since = "1.17.0")] pub fn replace(&self, val: T) -> T { // SAFETY: This can cause data races if called from a separate thread, @@ -614,6 +615,7 @@ impl<T, const N: usize> Cell<[T; N]> { /// A mutable memory location with dynamically checked borrow rules /// /// See the [module-level documentation](self) for more. +#[cfg_attr(not(test), rustc_diagnostic_item = "RefCell")] #[stable(feature = "rust1", since = "1.0.0")] pub struct RefCell<T: ?Sized> { borrow: Cell<BorrowFlag>, @@ -1021,15 +1023,18 @@ impl<T: ?Sized> RefCell<T> { /// Returns a mutable reference to the underlying data. /// - /// This call borrows `RefCell` mutably (at compile-time) so there is no - /// need for dynamic checks. + /// Since this method borrows `RefCell` mutably, it is statically guaranteed + /// that no borrows to the underlying data exist. The dynamic checks inherent + /// in [`borrow_mut`] and most other methods of `RefCell` are therefor + /// unnecessary. /// - /// However be cautious: this method expects `self` to be mutable, which is - /// generally not the case when using a `RefCell`. Take a look at the - /// [`borrow_mut`] method instead if `self` isn't mutable. + /// This method can only be called if `RefCell` can be mutably borrowed, + /// which in general is only the case directly after the `RefCell` has + /// been created. In these situations, skipping the aforementioned dynamic + /// borrowing checks may yield better ergonomics and runtime-performance. /// - /// Also, please be aware that this method is only for special circumstances and is usually - /// not what you want. In case of doubt, use [`borrow_mut`] instead. + /// In most situations where `RefCell` is used, it can't be borrowed mutably. + /// Use [`borrow_mut`] to get mutable access to the underlying data then. /// /// [`borrow_mut`]: RefCell::borrow_mut() /// @@ -1811,6 +1816,61 @@ impl<T: ?Sized + fmt::Display> fmt::Display for RefMut<'_, T> { /// /// [`.get_mut()`]: `UnsafeCell::get_mut` /// +/// # Memory layout +/// +/// `UnsafeCell<T>` has the same in-memory representation as its inner type `T`. A consequence +/// of this guarantee is that it is possible to convert between `T` and `UnsafeCell<T>`. +/// Special care has to be taken when converting a nested `T` inside of an `Outer<T>` type +/// to an `Outer<UnsafeCell<T>>` type: this is not sound when the `Outer<T>` type enables [niche] +/// optimizations. For example, the type `Option<NonNull<u8>>` is typically 8 bytes large on +/// 64-bit platforms, but the type `Option<UnsafeCell<NonNull<u8>>>` takes up 16 bytes of space. +/// Therefore this is not a valid conversion, despite `NonNull<u8>` and `UnsafeCell<NonNull<u8>>>` +/// having the same memory layout. This is because `UnsafeCell` disables niche optimizations in +/// order to avoid its interior mutability property from spreading from `T` into the `Outer` type, +/// thus this can cause distortions in the type size in these cases. +/// +/// Note that the only valid way to obtain a `*mut T` pointer to the contents of a +/// _shared_ `UnsafeCell<T>` is through [`.get()`] or [`.raw_get()`]. A `&mut T` reference +/// can be obtained by either dereferencing this pointer or by calling [`.get_mut()`] +/// on an _exclusive_ `UnsafeCell<T>`. Even though `T` and `UnsafeCell<T>` have the +/// same memory layout, the following is not allowed and undefined behavior: +/// +/// ```rust,no_run +/// # use std::cell::UnsafeCell; +/// unsafe fn not_allowed<T>(ptr: &UnsafeCell<T>) -> &mut T { +/// let t = ptr as *const UnsafeCell<T> as *mut T; +/// // This is undefined behavior, because the `*mut T` pointer +/// // was not obtained through `.get()` nor `.raw_get()`: +/// unsafe { &mut *t } +/// } +/// ``` +/// +/// Instead, do this: +/// +/// ```rust +/// # use std::cell::UnsafeCell; +/// // Safety: the caller must ensure that there are no references that +/// // point to the *contents* of the `UnsafeCell`. +/// unsafe fn get_mut<T>(ptr: &UnsafeCell<T>) -> &mut T { +/// unsafe { &mut *ptr.get() } +/// } +/// ``` +/// +/// Coverting in the other direction from a `&mut T` +/// to an `&UnsafeCell<T>` is allowed: +/// +/// ```rust +/// # use std::cell::UnsafeCell; +/// fn get_shared<T>(ptr: &mut T) -> &UnsafeCell<T> { +/// let t = ptr as *mut T as *const UnsafeCell<T>; +/// // SAFETY: `T` and `UnsafeCell<T>` have the same memory layout +/// unsafe { &*t } +/// } +/// ``` +/// +/// [niche]: https://rust-lang.github.io/unsafe-code-guidelines/glossary.html#niche +/// [`.raw_get()`]: `UnsafeCell::raw_get` +/// /// # Examples /// /// Here is an example showcasing how to soundly mutate the contents of an `UnsafeCell<_>` despite diff --git a/library/core/src/char/decode.rs b/library/core/src/char/decode.rs index 71297acd1..11f1c30f6 100644 --- a/library/core/src/char/decode.rs +++ b/library/core/src/char/decode.rs @@ -1,5 +1,6 @@ //! UTF-8 and UTF-16 decoding iterators +use crate::error::Error; use crate::fmt; use super::from_u32_unchecked; @@ -121,3 +122,11 @@ impl fmt::Display for DecodeUtf16Error { write!(f, "unpaired surrogate found: {:x}", self.code) } } + +#[stable(feature = "decode_utf16", since = "1.9.0")] +impl Error for DecodeUtf16Error { + #[allow(deprecated)] + fn description(&self) -> &str { + "unpaired surrogate found" + } +} diff --git a/library/core/src/char/methods.rs b/library/core/src/char/methods.rs index eae567cad..bb8359936 100644 --- a/library/core/src/char/methods.rs +++ b/library/core/src/char/methods.rs @@ -597,9 +597,14 @@ impl char { /// Returns the number of 16-bit code units this `char` would need if /// encoded in UTF-16. /// + /// That number of code units is always either 1 or 2, for unicode scalar values in + /// the [basic multilingual plane] or [supplementary planes] respectively. + /// /// See the documentation for [`len_utf8()`] for more explanation of this /// concept. This function is a mirror, but for UTF-16 instead of UTF-8. /// + /// [basic multilingual plane]: http://www.unicode.org/glossary/#basic_multilingual_plane + /// [supplementary planes]: http://www.unicode.org/glossary/#supplementary_planes /// [`len_utf8()`]: #method.len_utf8 /// /// # Examples @@ -746,10 +751,19 @@ impl char { /// assert!(!'中'.is_lowercase()); /// assert!(!' '.is_lowercase()); /// ``` + /// + /// In a const context: + /// + /// ``` + /// #![feature(const_unicode_case_lookup)] + /// const CAPITAL_DELTA_IS_LOWERCASE: bool = 'Δ'.is_lowercase(); + /// assert!(!CAPITAL_DELTA_IS_LOWERCASE); + /// ``` #[must_use] #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_unicode_case_lookup", issue = "101400")] #[inline] - pub fn is_lowercase(self) -> bool { + pub const fn is_lowercase(self) -> bool { match self { 'a'..='z' => true, c => c > '\x7f' && unicode::Lowercase(c), @@ -779,10 +793,19 @@ impl char { /// assert!(!'中'.is_uppercase()); /// assert!(!' '.is_uppercase()); /// ``` + /// + /// In a const context: + /// + /// ``` + /// #![feature(const_unicode_case_lookup)] + /// const CAPITAL_DELTA_IS_UPPERCASE: bool = 'Δ'.is_uppercase(); + /// assert!(CAPITAL_DELTA_IS_UPPERCASE); + /// ``` #[must_use] #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_unicode_case_lookup", issue = "101400")] #[inline] - pub fn is_uppercase(self) -> bool { + pub const fn is_uppercase(self) -> bool { match self { 'A'..='Z' => true, c => c > '\x7f' && unicode::Uppercase(c), @@ -892,8 +915,7 @@ impl char { /// /// The general categories for numbers (`Nd` for decimal digits, `Nl` for letter-like numeric /// characters, and `No` for other numeric characters) are specified in the [Unicode Character - /// Database][ucd] [`UnicodeData.txt`]. Note that this means ideographic numbers like '三' - /// are considered alphabetic, not numeric. Please consider to use `is_ascii_digit` or `is_digit`. + /// Database][ucd] [`UnicodeData.txt`]. /// /// This method doesn't cover everything that could be considered a number, e.g. ideographic numbers like '三'. /// If you want everything including characters with overlapping purposes then you might want to use @@ -1427,6 +1449,38 @@ impl char { matches!(*self, '0'..='9') } + /// Checks if the value is an ASCII octal digit: + /// U+0030 '0' ..= U+0037 '7'. + /// + /// # Examples + /// + /// ``` + /// #![feature(is_ascii_octdigit)] + /// + /// let uppercase_a = 'A'; + /// let a = 'a'; + /// let zero = '0'; + /// let seven = '7'; + /// let nine = '9'; + /// let percent = '%'; + /// let lf = '\n'; + /// + /// assert!(!uppercase_a.is_ascii_octdigit()); + /// assert!(!a.is_ascii_octdigit()); + /// assert!(zero.is_ascii_octdigit()); + /// assert!(seven.is_ascii_octdigit()); + /// assert!(!nine.is_ascii_octdigit()); + /// assert!(!percent.is_ascii_octdigit()); + /// assert!(!lf.is_ascii_octdigit()); + /// ``` + #[must_use] + #[unstable(feature = "is_ascii_octdigit", issue = "101288")] + #[rustc_const_unstable(feature = "is_ascii_octdigit", issue = "101288")] + #[inline] + pub const fn is_ascii_octdigit(&self) -> bool { + matches!(*self, '0'..='7') + } + /// Checks if the value is an ASCII hexadecimal digit: /// /// - U+0030 '0' ..= U+0039 '9', or diff --git a/library/core/src/char/mod.rs b/library/core/src/char/mod.rs index 0df23e7bb..b34a71216 100644 --- a/library/core/src/char/mod.rs +++ b/library/core/src/char/mod.rs @@ -1,4 +1,6 @@ -//! A character type. +//! Utilities for the `char` primitive type. +//! +//! *[See also the `char` primitive type](primitive@char).* //! //! The `char` type represents a single character. More specifically, since //! 'character' isn't a well-defined concept in Unicode, `char` is a '[Unicode @@ -36,6 +38,7 @@ pub use self::methods::encode_utf16_raw; #[unstable(feature = "char_internals", reason = "exposed only for libstd", issue = "none")] pub use self::methods::encode_utf8_raw; +use crate::error::Error; use crate::fmt::{self, Write}; use crate::iter::FusedIterator; @@ -582,3 +585,6 @@ impl fmt::Display for TryFromCharError { "unicode code point out of range".fmt(fmt) } } + +#[stable(feature = "u8_from_char", since = "1.59.0")] +impl Error for TryFromCharError {} diff --git a/library/core/src/cmp.rs b/library/core/src/cmp.rs index 20bb67687..f0fa2e1d2 100644 --- a/library/core/src/cmp.rs +++ b/library/core/src/cmp.rs @@ -1,6 +1,6 @@ -//! Functionality for ordering and comparison. +//! Utilities for comparing and ordering values. //! -//! This module contains various tools for ordering and comparing values. In +//! This module contains various tools for comparing and ordering values. In //! summary: //! //! * [`Eq`] and [`PartialEq`] are traits that allow you to define total and @@ -22,7 +22,9 @@ #![stable(feature = "rust1", since = "1.0.0")] +use crate::const_closure::ConstFnMutClosure; use crate::marker::Destruct; +use crate::marker::StructuralPartialEq; use self::Ordering::*; @@ -38,8 +40,10 @@ use self::Ordering::*; /// /// Implementations must ensure that `eq` and `ne` are consistent with each other: /// -/// - `a != b` if and only if `!(a == b)` -/// (ensured by the default implementation). +/// - `a != b` if and only if `!(a == b)`. +/// +/// The default implementation of `ne` provides this consistency and is almost +/// always sufficient. It should not be overridden without very good reason. /// /// If [`PartialOrd`] or [`Ord`] are also implemented for `Self` and `Rhs`, their methods must also /// be consistent with `PartialEq` (see the documentation of those traits for the exact @@ -201,20 +205,10 @@ use self::Ordering::*; #[stable(feature = "rust1", since = "1.0.0")] #[doc(alias = "==")] #[doc(alias = "!=")] -#[cfg_attr( - bootstrap, - rustc_on_unimplemented( - message = "can't compare `{Self}` with `{Rhs}`", - label = "no implementation for `{Self} == {Rhs}`" - ) -)] -#[cfg_attr( - not(bootstrap), - rustc_on_unimplemented( - message = "can't compare `{Self}` with `{Rhs}`", - label = "no implementation for `{Self} == {Rhs}`", - append_const_msg, - ) +#[rustc_on_unimplemented( + message = "can't compare `{Self}` with `{Rhs}`", + label = "no implementation for `{Self} == {Rhs}`", + append_const_msg )] #[const_trait] #[rustc_diagnostic_item = "PartialEq"] @@ -225,7 +219,8 @@ pub trait PartialEq<Rhs: ?Sized = Self> { #[stable(feature = "rust1", since = "1.0.0")] fn eq(&self, other: &Rhs) -> bool; - /// This method tests for `!=`. + /// This method tests for `!=`. The default implementation is almost always + /// sufficient, and should not be overridden without very good reason. #[inline] #[must_use] #[stable(feature = "rust1", since = "1.0.0")] @@ -335,7 +330,7 @@ pub struct AssertParamIsEq<T: Eq + ?Sized> { /// let result = 2.cmp(&1); /// assert_eq!(Ordering::Greater, result); /// ``` -#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)] +#[derive(Clone, Copy, Eq, Debug, Hash)] #[stable(feature = "rust1", since = "1.0.0")] #[repr(i8)] pub enum Ordering { @@ -882,6 +877,18 @@ pub macro Ord($item:item) { } #[stable(feature = "rust1", since = "1.0.0")] +impl StructuralPartialEq for Ordering {} + +#[stable(feature = "rust1", since = "1.0.0")] +#[rustc_const_unstable(feature = "const_cmp", issue = "92391")] +impl const PartialEq for Ordering { + #[inline] + fn eq(&self, other: &Self) -> bool { + (*self as i32).eq(&(*other as i32)) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_unstable(feature = "const_cmp", issue = "92391")] impl const Ord for Ordering { #[inline] @@ -1060,20 +1067,10 @@ impl const PartialOrd for Ordering { #[doc(alias = "<")] #[doc(alias = "<=")] #[doc(alias = ">=")] -#[cfg_attr( - bootstrap, - rustc_on_unimplemented( - message = "can't compare `{Self}` with `{Rhs}`", - label = "no implementation for `{Self} < {Rhs}` and `{Self} > {Rhs}`", - ) -)] -#[cfg_attr( - not(bootstrap), - rustc_on_unimplemented( - message = "can't compare `{Self}` with `{Rhs}`", - label = "no implementation for `{Self} < {Rhs}` and `{Self} > {Rhs}`", - append_const_msg, - ) +#[rustc_on_unimplemented( + message = "can't compare `{Self}` with `{Rhs}`", + label = "no implementation for `{Self} < {Rhs}` and `{Self} > {Rhs}`", + append_const_msg )] #[const_trait] #[rustc_diagnostic_item = "PartialOrd"] @@ -1139,11 +1136,7 @@ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> { #[must_use] #[stable(feature = "rust1", since = "1.0.0")] fn le(&self, other: &Rhs) -> bool { - // Pattern `Some(Less | Eq)` optimizes worse than negating `None | Some(Greater)`. - // FIXME: The root cause was fixed upstream in LLVM with: - // https://github.com/llvm/llvm-project/commit/9bad7de9a3fb844f1ca2965f35d0c2a3d1e11775 - // Revert this workaround once support for LLVM 12 gets dropped. - !matches!(self.partial_cmp(other), None | Some(Greater)) + matches!(self.partial_cmp(other), Some(Less | Equal)) } /// This method tests greater than (for `self` and `other`) and is used by the `>` operator. @@ -1230,7 +1223,12 @@ pub const fn min<T: ~const Ord + ~const Destruct>(v1: T, v2: T) -> T { #[inline] #[must_use] #[stable(feature = "cmp_min_max_by", since = "1.53.0")] -pub fn min_by<T, F: FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T { +#[rustc_const_unstable(feature = "const_cmp", issue = "92391")] +pub const fn min_by<T, F: ~const FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T +where + T: ~const Destruct, + F: ~const Destruct, +{ match compare(&v1, &v2) { Ordering::Less | Ordering::Equal => v1, Ordering::Greater => v2, @@ -1252,8 +1250,24 @@ pub fn min_by<T, F: FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T { #[inline] #[must_use] #[stable(feature = "cmp_min_max_by", since = "1.53.0")] -pub fn min_by_key<T, F: FnMut(&T) -> K, K: Ord>(v1: T, v2: T, mut f: F) -> T { - min_by(v1, v2, |v1, v2| f(v1).cmp(&f(v2))) +#[rustc_const_unstable(feature = "const_cmp", issue = "92391")] +pub const fn min_by_key<T, F: ~const FnMut(&T) -> K, K: ~const Ord>(v1: T, v2: T, mut f: F) -> T +where + T: ~const Destruct, + F: ~const Destruct, + K: ~const Destruct, +{ + const fn imp<T, F: ~const FnMut(&T) -> K, K: ~const Ord>( + f: &mut F, + (v1, v2): (&T, &T), + ) -> Ordering + where + T: ~const Destruct, + K: ~const Destruct, + { + f(v1).cmp(&f(v2)) + } + min_by(v1, v2, ConstFnMutClosure::new(&mut f, imp)) } /// Compares and returns the maximum of two values. @@ -1294,7 +1308,12 @@ pub const fn max<T: ~const Ord + ~const Destruct>(v1: T, v2: T) -> T { #[inline] #[must_use] #[stable(feature = "cmp_min_max_by", since = "1.53.0")] -pub fn max_by<T, F: FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T { +#[rustc_const_unstable(feature = "const_cmp", issue = "92391")] +pub const fn max_by<T, F: ~const FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T +where + T: ~const Destruct, + F: ~const Destruct, +{ match compare(&v1, &v2) { Ordering::Less | Ordering::Equal => v2, Ordering::Greater => v1, @@ -1316,8 +1335,24 @@ pub fn max_by<T, F: FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T { #[inline] #[must_use] #[stable(feature = "cmp_min_max_by", since = "1.53.0")] -pub fn max_by_key<T, F: FnMut(&T) -> K, K: Ord>(v1: T, v2: T, mut f: F) -> T { - max_by(v1, v2, |v1, v2| f(v1).cmp(&f(v2))) +#[rustc_const_unstable(feature = "const_cmp", issue = "92391")] +pub const fn max_by_key<T, F: ~const FnMut(&T) -> K, K: ~const Ord>(v1: T, v2: T, mut f: F) -> T +where + T: ~const Destruct, + F: ~const Destruct, + K: ~const Destruct, +{ + const fn imp<T, F: ~const FnMut(&T) -> K, K: ~const Ord>( + f: &mut F, + (v1, v2): (&T, &T), + ) -> Ordering + where + T: ~const Destruct, + K: ~const Destruct, + { + f(v1).cmp(&f(v2)) + } + max_by(v1, v2, ConstFnMutClosure::new(&mut f, imp)) } // Implementation of PartialEq, Eq, PartialOrd and Ord for primitive types diff --git a/library/core/src/const_closure.rs b/library/core/src/const_closure.rs new file mode 100644 index 000000000..9e9c02093 --- /dev/null +++ b/library/core/src/const_closure.rs @@ -0,0 +1,77 @@ +use crate::marker::Destruct; + +/// Struct representing a closure with mutably borrowed data. +/// +/// Example: +/// ```no_build +/// #![feature(const_mut_refs)] +/// use crate::const_closure::ConstFnMutClosure; +/// const fn imp(state: &mut i32, (arg,): (i32,)) -> i32 { +/// *state += arg; +/// *state +/// } +/// let mut i = 5; +/// let mut cl = ConstFnMutClosure::new(&mut i, imp); +/// +/// assert!(7 == cl(2)); +/// assert!(8 == cl(1)); +/// ``` +pub(crate) struct ConstFnMutClosure<CapturedData, Function> { + /// The Data captured by the Closure. + /// Must be either a (mutable) reference or a tuple of (mutable) references. + pub data: CapturedData, + /// The Function of the Closure, must be: Fn(CapturedData, ClosureArgs) -> ClosureReturn + pub func: Function, +} +impl<'a, CapturedData: ?Sized, Function> ConstFnMutClosure<&'a mut CapturedData, Function> { + /// Function for creating a new closure. + /// + /// `data` is the a mutable borrow of data that is captured from the environment. + /// If you want Data to be a tuple of mutable Borrows, the struct must be constructed manually. + /// + /// `func` is the function of the closure, it gets the data and a tuple of the arguments closure + /// and return the return value of the closure. + pub(crate) const fn new<ClosureArguments, ClosureReturnValue>( + data: &'a mut CapturedData, + func: Function, + ) -> Self + where + Function: ~const Fn(&mut CapturedData, ClosureArguments) -> ClosureReturnValue, + { + Self { data, func } + } +} + +macro_rules! impl_fn_mut_tuple { + ($($var:ident)*) => { + #[allow(unused_parens)] + impl<'a, $($var,)* ClosureArguments, Function, ClosureReturnValue> const + FnOnce<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function> + where + Function: ~const Fn(($(&mut $var),*), ClosureArguments) -> ClosureReturnValue+ ~const Destruct, + { + type Output = ClosureReturnValue; + + extern "rust-call" fn call_once(mut self, args: ClosureArguments) -> Self::Output { + self.call_mut(args) + } + } + #[allow(unused_parens)] + impl<'a, $($var,)* ClosureArguments, Function, ClosureReturnValue> const + FnMut<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function> + where + Function: ~const Fn(($(&mut $var),*), ClosureArguments)-> ClosureReturnValue, + { + extern "rust-call" fn call_mut(&mut self, args: ClosureArguments) -> Self::Output { + #[allow(non_snake_case)] + let ($($var),*) = &mut self.data; + (self.func)(($($var),*), args) + } + } + }; +} +impl_fn_mut_tuple!(A); +impl_fn_mut_tuple!(A B); +impl_fn_mut_tuple!(A B C); +impl_fn_mut_tuple!(A B C D); +impl_fn_mut_tuple!(A B C D E); diff --git a/library/core/src/convert/mod.rs b/library/core/src/convert/mod.rs index b30c8a4ae..33493964b 100644 --- a/library/core/src/convert/mod.rs +++ b/library/core/src/convert/mod.rs @@ -25,6 +25,7 @@ //! # Generic Implementations //! //! - [`AsRef`] and [`AsMut`] auto-dereference if the inner type is a reference +//! (but not generally for all [dereferenceable types][core::ops::Deref]) //! - [`From`]`<U> for T` implies [`Into`]`<T> for U` //! - [`TryFrom`]`<U> for T` implies [`TryInto`]`<T> for U` //! - [`From`] and [`Into`] are reflexive, which means that all types can @@ -34,6 +35,7 @@ #![stable(feature = "rust1", since = "1.0.0")] +use crate::error::Error; use crate::fmt; use crate::hash::{Hash, Hasher}; @@ -108,10 +110,12 @@ pub const fn identity<T>(x: T) -> T { /// If you need to do a costly conversion it is better to implement [`From`] with type /// `&T` or write a custom function. /// +/// # Relation to `Borrow` +/// /// `AsRef` has the same signature as [`Borrow`], but [`Borrow`] is different in a few aspects: /// /// - Unlike `AsRef`, [`Borrow`] has a blanket impl for any `T`, and can be used to accept either -/// a reference or a value. +/// a reference or a value. (See also note on `AsRef`'s reflexibility below.) /// - [`Borrow`] also requires that [`Hash`], [`Eq`] and [`Ord`] for a borrowed value are /// equivalent to those of the owned value. For this reason, if you want to /// borrow only a single field of a struct you can implement `AsRef`, but not [`Borrow`]. @@ -121,9 +125,66 @@ pub const fn identity<T>(x: T) -> T { /// /// # Generic Implementations /// -/// - `AsRef` auto-dereferences if the inner type is a reference or a mutable -/// reference (e.g.: `foo.as_ref()` will work the same if `foo` has type -/// `&mut Foo` or `&&mut Foo`) +/// `AsRef` auto-dereferences if the inner type is a reference or a mutable reference +/// (e.g.: `foo.as_ref()` will work the same if `foo` has type `&mut Foo` or `&&mut Foo`). +/// +/// Note that due to historic reasons, the above currently does not hold generally for all +/// [dereferenceable types], e.g. `foo.as_ref()` will *not* work the same as +/// `Box::new(foo).as_ref()`. Instead, many smart pointers provide an `as_ref` implementation which +/// simply returns a reference to the [pointed-to value] (but do not perform a cheap +/// reference-to-reference conversion for that value). However, [`AsRef::as_ref`] should not be +/// used for the sole purpose of dereferencing; instead ['`Deref` coercion'] can be used: +/// +/// [dereferenceable types]: core::ops::Deref +/// [pointed-to value]: core::ops::Deref::Target +/// ['`Deref` coercion']: core::ops::Deref#more-on-deref-coercion +/// +/// ``` +/// let x = Box::new(5i32); +/// // Avoid this: +/// // let y: &i32 = x.as_ref(); +/// // Better just write: +/// let y: &i32 = &x; +/// ``` +/// +/// Types which implement [`Deref`] should consider implementing `AsRef<T>` as follows: +/// +/// [`Deref`]: core::ops::Deref +/// +/// ``` +/// # use core::ops::Deref; +/// # struct SomeType; +/// # impl Deref for SomeType { +/// # type Target = [u8]; +/// # fn deref(&self) -> &[u8] { +/// # &[] +/// # } +/// # } +/// impl<T> AsRef<T> for SomeType +/// where +/// T: ?Sized, +/// <SomeType as Deref>::Target: AsRef<T>, +/// { +/// fn as_ref(&self) -> &T { +/// self.deref().as_ref() +/// } +/// } +/// ``` +/// +/// # Reflexivity +/// +/// Ideally, `AsRef` would be reflexive, i.e. there would be an `impl<T: ?Sized> AsRef<T> for T` +/// with [`as_ref`] simply returning its argument unchanged. +/// Such a blanket implementation is currently *not* provided due to technical restrictions of +/// Rust's type system (it would be overlapping with another existing blanket implementation for +/// `&T where T: AsRef<U>` which allows `AsRef` to auto-dereference, see "Generic Implementations" +/// above). +/// +/// [`as_ref`]: AsRef::as_ref +/// +/// A trivial implementation of `AsRef<T> for T` must be added explicitly for a particular type `T` +/// where needed or desired. Note, however, that not all types from `std` contain such an +/// implementation, and those cannot be added by external code due to orphan rules. /// /// # Examples /// @@ -153,6 +214,7 @@ pub const fn identity<T>(x: T) -> T { /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[cfg_attr(not(test), rustc_diagnostic_item = "AsRef")] +#[const_trait] pub trait AsRef<T: ?Sized> { /// Converts this type into a shared reference of the (usually inferred) input type. #[stable(feature = "rust1", since = "1.0.0")] @@ -170,31 +232,141 @@ pub trait AsRef<T: ?Sized> { /// /// # Generic Implementations /// -/// - `AsMut` auto-dereferences if the inner type is a mutable reference -/// (e.g.: `foo.as_mut()` will work the same if `foo` has type `&mut Foo` -/// or `&mut &mut Foo`) +/// `AsMut` auto-dereferences if the inner type is a mutable reference +/// (e.g.: `foo.as_mut()` will work the same if `foo` has type `&mut Foo` or `&mut &mut Foo`). +/// +/// Note that due to historic reasons, the above currently does not hold generally for all +/// [mutably dereferenceable types], e.g. `foo.as_mut()` will *not* work the same as +/// `Box::new(foo).as_mut()`. Instead, many smart pointers provide an `as_mut` implementation which +/// simply returns a reference to the [pointed-to value] (but do not perform a cheap +/// reference-to-reference conversion for that value). However, [`AsMut::as_mut`] should not be +/// used for the sole purpose of mutable dereferencing; instead ['`Deref` coercion'] can be used: +/// +/// [mutably dereferenceable types]: core::ops::DerefMut +/// [pointed-to value]: core::ops::Deref::Target +/// ['`Deref` coercion']: core::ops::DerefMut#more-on-deref-coercion +/// +/// ``` +/// let mut x = Box::new(5i32); +/// // Avoid this: +/// // let y: &mut i32 = x.as_mut(); +/// // Better just write: +/// let y: &mut i32 = &mut x; +/// ``` +/// +/// Types which implement [`DerefMut`] should consider to add an implementation of `AsMut<T>` as +/// follows: +/// +/// [`DerefMut`]: core::ops::DerefMut +/// +/// ``` +/// # use core::ops::{Deref, DerefMut}; +/// # struct SomeType; +/// # impl Deref for SomeType { +/// # type Target = [u8]; +/// # fn deref(&self) -> &[u8] { +/// # &[] +/// # } +/// # } +/// # impl DerefMut for SomeType { +/// # fn deref_mut(&mut self) -> &mut [u8] { +/// # &mut [] +/// # } +/// # } +/// impl<T> AsMut<T> for SomeType +/// where +/// <SomeType as Deref>::Target: AsMut<T>, +/// { +/// fn as_mut(&mut self) -> &mut T { +/// self.deref_mut().as_mut() +/// } +/// } +/// ``` +/// +/// # Reflexivity +/// +/// Ideally, `AsMut` would be reflexive, i.e. there would be an `impl<T: ?Sized> AsMut<T> for T` +/// with [`as_mut`] simply returning its argument unchanged. +/// Such a blanket implementation is currently *not* provided due to technical restrictions of +/// Rust's type system (it would be overlapping with another existing blanket implementation for +/// `&mut T where T: AsMut<U>` which allows `AsMut` to auto-dereference, see "Generic +/// Implementations" above). +/// +/// [`as_mut`]: AsMut::as_mut +/// +/// A trivial implementation of `AsMut<T> for T` must be added explicitly for a particular type `T` +/// where needed or desired. Note, however, that not all types from `std` contain such an +/// implementation, and those cannot be added by external code due to orphan rules. /// /// # Examples /// -/// Using `AsMut` as trait bound for a generic function we can accept all mutable references -/// that can be converted to type `&mut T`. Because [`Box<T>`] implements `AsMut<T>` we can -/// write a function `add_one` that takes all arguments that can be converted to `&mut u64`. -/// Because [`Box<T>`] implements `AsMut<T>`, `add_one` accepts arguments of type -/// `&mut Box<u64>` as well: +/// Using `AsMut` as trait bound for a generic function, we can accept all mutable references that +/// can be converted to type `&mut T`. Unlike [dereference], which has a single [target type], +/// there can be multiple implementations of `AsMut` for a type. In particular, `Vec<T>` implements +/// both `AsMut<Vec<T>>` and `AsMut<[T]>`. +/// +/// In the following, the example functions `caesar` and `null_terminate` provide a generic +/// interface which work with any type that can be converted by cheap mutable-to-mutable conversion +/// into a byte slice (`[u8]`) or byte vector (`Vec<u8>`), respectively. +/// +/// [dereference]: core::ops::DerefMut +/// [target type]: core::ops::Deref::Target /// /// ``` -/// fn add_one<T: AsMut<u64>>(num: &mut T) { -/// *num.as_mut() += 1; +/// struct Document { +/// info: String, +/// content: Vec<u8>, +/// } +/// +/// impl<T: ?Sized> AsMut<T> for Document +/// where +/// Vec<u8>: AsMut<T>, +/// { +/// fn as_mut(&mut self) -> &mut T { +/// self.content.as_mut() +/// } /// } /// -/// let mut boxed_num = Box::new(0); -/// add_one(&mut boxed_num); -/// assert_eq!(*boxed_num, 1); +/// fn caesar<T: AsMut<[u8]>>(data: &mut T, key: u8) { +/// for byte in data.as_mut() { +/// *byte = byte.wrapping_add(key); +/// } +/// } +/// +/// fn null_terminate<T: AsMut<Vec<u8>>>(data: &mut T) { +/// // Using a non-generic inner function, which contains most of the +/// // functionality, helps to minimize monomorphization overhead. +/// fn doit(data: &mut Vec<u8>) { +/// let len = data.len(); +/// if len == 0 || data[len-1] != 0 { +/// data.push(0); +/// } +/// } +/// doit(data.as_mut()); +/// } +/// +/// fn main() { +/// let mut v: Vec<u8> = vec![1, 2, 3]; +/// caesar(&mut v, 5); +/// assert_eq!(v, [6, 7, 8]); +/// null_terminate(&mut v); +/// assert_eq!(v, [6, 7, 8, 0]); +/// let mut doc = Document { +/// info: String::from("Example"), +/// content: vec![17, 19, 8], +/// }; +/// caesar(&mut doc, 1); +/// assert_eq!(doc.content, [18, 20, 9]); +/// null_terminate(&mut doc); +/// assert_eq!(doc.content, [18, 20, 9, 0]); +/// } /// ``` /// -/// [`Box<T>`]: ../../std/boxed/struct.Box.html +/// Note, however, that APIs don't need to be generic. In many cases taking a `&mut [u8]` or +/// `&mut Vec<u8>`, for example, is the better choice (callers need to pass the correct type then). #[stable(feature = "rust1", since = "1.0.0")] #[cfg_attr(not(test), rustc_diagnostic_item = "AsMut")] +#[const_trait] pub trait AsMut<T: ?Sized> { /// Converts this type into a mutable reference of the (usually inferred) input type. #[stable(feature = "rust1", since = "1.0.0")] @@ -271,6 +443,7 @@ pub trait AsMut<T: ?Sized> { /// [`Vec`]: ../../std/vec/struct.Vec.html #[rustc_diagnostic_item = "Into"] #[stable(feature = "rust1", since = "1.0.0")] +#[const_trait] pub trait Into<T>: Sized { /// Converts this type into the (usually inferred) input type. #[must_use] @@ -366,12 +539,13 @@ pub trait Into<T>: Sized { all(_Self = "&str", T = "std::string::String"), note = "to coerce a `{T}` into a `{Self}`, use `&*` as a prefix", ))] +#[const_trait] pub trait From<T>: Sized { /// Converts to this type from the input type. #[lang = "from"] #[must_use] #[stable(feature = "rust1", since = "1.0.0")] - fn from(_: T) -> Self; + fn from(value: T) -> Self; } /// An attempted conversion that consumes `self`, which may or may not be @@ -390,6 +564,7 @@ pub trait From<T>: Sized { /// [`Into`], see there for details. #[rustc_diagnostic_item = "TryInto"] #[stable(feature = "try_from", since = "1.34.0")] +#[const_trait] pub trait TryInto<T>: Sized { /// The type returned in the event of a conversion error. #[stable(feature = "try_from", since = "1.34.0")] @@ -434,7 +609,7 @@ pub trait TryInto<T>: Sized { /// /// fn try_from(value: i32) -> Result<Self, Self::Error> { /// if value <= 0 { -/// Err("GreaterThanZero only accepts value superior than zero!") +/// Err("GreaterThanZero only accepts values greater than zero!") /// } else { /// Ok(GreaterThanZero(value)) /// } @@ -466,6 +641,7 @@ pub trait TryInto<T>: Sized { /// [`try_from`]: TryFrom::try_from #[rustc_diagnostic_item = "TryFrom"] #[stable(feature = "try_from", since = "1.34.0")] +#[const_trait] pub trait TryFrom<T>: Sized { /// The type returned in the event of a conversion error. #[stable(feature = "try_from", since = "1.34.0")] @@ -556,6 +732,7 @@ where #[rustc_const_unstable(feature = "const_convert", issue = "88674")] impl<T> const From<T> for T { /// Returns the argument unchanged. + #[inline(always)] fn from(t: T) -> T { t } @@ -715,6 +892,13 @@ impl fmt::Display for Infallible { } } +#[stable(feature = "str_parse_error2", since = "1.8.0")] +impl Error for Infallible { + fn description(&self) -> &str { + match *self {} + } +} + #[stable(feature = "convert_infallible", since = "1.34.0")] impl PartialEq for Infallible { fn eq(&self, _: &Infallible) -> bool { diff --git a/library/core/src/default.rs b/library/core/src/default.rs index 1ce00828b..a5b4e9655 100644 --- a/library/core/src/default.rs +++ b/library/core/src/default.rs @@ -1,4 +1,4 @@ -//! The `Default` trait for types which may have meaningful default values. +//! The `Default` trait for types with a default value. #![stable(feature = "rust1", since = "1.0.0")] @@ -99,6 +99,7 @@ /// ``` #[cfg_attr(not(test), rustc_diagnostic_item = "Default")] #[stable(feature = "rust1", since = "1.0.0")] +#[cfg_attr(not(bootstrap), const_trait)] pub trait Default: Sized { /// Returns the "default value" for a type. /// diff --git a/library/core/src/error.md b/library/core/src/error.md new file mode 100644 index 000000000..891abebbf --- /dev/null +++ b/library/core/src/error.md @@ -0,0 +1,137 @@ +Interfaces for working with Errors. + +# Error Handling In Rust + +The Rust language provides two complementary systems for constructing / +representing, reporting, propagating, reacting to, and discarding errors. +These responsibilities are collectively known as "error handling." The +components of the first system, the panic runtime and interfaces, are most +commonly used to represent bugs that have been detected in your program. The +components of the second system, `Result`, the error traits, and user +defined types, are used to represent anticipated runtime failure modes of +your program. + +## The Panic Interfaces + +The following are the primary interfaces of the panic system and the +responsibilities they cover: + +* [`panic!`] and [`panic_any`] (Constructing, Propagated automatically) +* [`PanicInfo`] (Reporting) +* [`set_hook`], [`take_hook`], and [`#[panic_handler]`][panic-handler] (Reporting) +* [`catch_unwind`] and [`resume_unwind`] (Discarding, Propagating) + +The following are the primary interfaces of the error system and the +responsibilities they cover: + +* [`Result`] (Propagating, Reacting) +* The [`Error`] trait (Reporting) +* User defined types (Constructing / Representing) +* [`match`] and [`downcast`] (Reacting) +* The question mark operator ([`?`]) (Propagating) +* The partially stable [`Try`] traits (Propagating, Constructing) +* [`Termination`] (Reporting) + +## Converting Errors into Panics + +The panic and error systems are not entirely distinct. Often times errors +that are anticipated runtime failures in an API might instead represent bugs +to a caller. For these situations the standard library provides APIs for +constructing panics with an `Error` as it's source. + +* [`Result::unwrap`] +* [`Result::expect`] + +These functions are equivalent, they either return the inner value if the +`Result` is `Ok` or panic if the `Result` is `Err` printing the inner error +as the source. The only difference between them is that with `expect` you +provide a panic error message to be printed alongside the source, whereas +`unwrap` has a default message indicating only that you unwraped an `Err`. + +Of the two, `expect` is generally preferred since its `msg` field allows you +to convey your intent and assumptions which makes tracking down the source +of a panic easier. `unwrap` on the other hand can still be a good fit in +situations where you can trivially show that a piece of code will never +panic, such as `"127.0.0.1".parse::<std::net::IpAddr>().unwrap()` or early +prototyping. + +# Common Message Styles + +There are two common styles for how people word `expect` messages. Using +the message to present information to users encountering a panic +("expect as error message") or using the message to present information +to developers debugging the panic ("expect as precondition"). + +In the former case the expect message is used to describe the error that +has occurred which is considered a bug. Consider the following example: + +```should_panic +// Read environment variable, panic if it is not present +let path = std::env::var("IMPORTANT_PATH").unwrap(); +``` + +In the "expect as error message" style we would use expect to describe +that the environment variable was not set when it should have been: + +```should_panic +let path = std::env::var("IMPORTANT_PATH") + .expect("env variable `IMPORTANT_PATH` is not set"); +``` + +In the "expect as precondition" style, we would instead describe the +reason we _expect_ the `Result` should be `Ok`. With this style we would +prefer to write: + +```should_panic +let path = std::env::var("IMPORTANT_PATH") + .expect("env variable `IMPORTANT_PATH` should be set by `wrapper_script.sh`"); +``` + +The "expect as error message" style does not work as well with the +default output of the std panic hooks, and often ends up repeating +information that is already communicated by the source error being +unwrapped: + +```text +thread 'main' panicked at 'env variable `IMPORTANT_PATH` is not set: NotPresent', src/main.rs:4:6 +``` + +In this example we end up mentioning that an env variable is not set, +followed by our source message that says the env is not present, the +only additional information we're communicating is the name of the +environment variable being checked. + +The "expect as precondition" style instead focuses on source code +readability, making it easier to understand what must have gone wrong in +situations where panics are being used to represent bugs exclusively. +Also, by framing our expect in terms of what "SHOULD" have happened to +prevent the source error, we end up introducing new information that is +independent from our source error. + +```text +thread 'main' panicked at 'env variable `IMPORTANT_PATH` should be set by `wrapper_script.sh`: NotPresent', src/main.rs:4:6 +``` + +In this example we are communicating not only the name of the +environment variable that should have been set, but also an explanation +for why it should have been set, and we let the source error display as +a clear contradiction to our expectation. + +**Hint**: If you're having trouble remembering how to phrase +expect-as-precondition style error messages remember to focus on the word +"should" as in "env variable should be set by blah" or "the given binary +should be available and executable by the current user". + +[`panic_any`]: ../../std/panic/fn.panic_any.html +[`PanicInfo`]: crate::panic::PanicInfo +[`catch_unwind`]: ../../std/panic/fn.catch_unwind.html +[`resume_unwind`]: ../../std/panic/fn.resume_unwind.html +[`downcast`]: crate::error::Error +[`Termination`]: ../../std/process/trait.Termination.html +[`Try`]: crate::ops::Try +[panic hook]: ../../std/panic/fn.set_hook.html +[`set_hook`]: ../../std/panic/fn.set_hook.html +[`take_hook`]: ../../std/panic/fn.take_hook.html +[panic-handler]: <https://doc.rust-lang.org/nomicon/panic-handler.html> +[`match`]: ../../std/keyword.match.html +[`?`]: ../../std/result/index.html#the-question-mark-operator- diff --git a/library/core/src/error.rs b/library/core/src/error.rs new file mode 100644 index 000000000..2738b4994 --- /dev/null +++ b/library/core/src/error.rs @@ -0,0 +1,508 @@ +#![doc = include_str!("error.md")] +#![unstable(feature = "error_in_core", issue = "none")] + +#[cfg(test)] +mod tests; + +use crate::any::{Demand, Provider, TypeId}; +use crate::fmt::{Debug, Display}; + +/// `Error` is a trait representing the basic expectations for error values, +/// i.e., values of type `E` in [`Result<T, E>`]. +/// +/// Errors must describe themselves through the [`Display`] and [`Debug`] +/// traits. Error messages are typically concise lowercase sentences without +/// trailing punctuation: +/// +/// ``` +/// let err = "NaN".parse::<u32>().unwrap_err(); +/// assert_eq!(err.to_string(), "invalid digit found in string"); +/// ``` +/// +/// Errors may provide cause information. [`Error::source()`] is generally +/// used when errors cross "abstraction boundaries". If one module must report +/// an error that is caused by an error from a lower-level module, it can allow +/// accessing that error via [`Error::source()`]. This makes it possible for the +/// high-level module to provide its own errors while also revealing some of the +/// implementation for debugging. +#[stable(feature = "rust1", since = "1.0.0")] +#[cfg_attr(not(test), rustc_diagnostic_item = "Error")] +#[rustc_has_incoherent_inherent_impls] +pub trait Error: Debug + Display { + /// The lower-level source of this error, if any. + /// + /// # Examples + /// + /// ``` + /// use std::error::Error; + /// use std::fmt; + /// + /// #[derive(Debug)] + /// struct SuperError { + /// source: SuperErrorSideKick, + /// } + /// + /// impl fmt::Display for SuperError { + /// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + /// write!(f, "SuperError is here!") + /// } + /// } + /// + /// impl Error for SuperError { + /// fn source(&self) -> Option<&(dyn Error + 'static)> { + /// Some(&self.source) + /// } + /// } + /// + /// #[derive(Debug)] + /// struct SuperErrorSideKick; + /// + /// impl fmt::Display for SuperErrorSideKick { + /// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + /// write!(f, "SuperErrorSideKick is here!") + /// } + /// } + /// + /// impl Error for SuperErrorSideKick {} + /// + /// fn get_super_error() -> Result<(), SuperError> { + /// Err(SuperError { source: SuperErrorSideKick }) + /// } + /// + /// fn main() { + /// match get_super_error() { + /// Err(e) => { + /// println!("Error: {e}"); + /// println!("Caused by: {}", e.source().unwrap()); + /// } + /// _ => println!("No error"), + /// } + /// } + /// ``` + #[stable(feature = "error_source", since = "1.30.0")] + fn source(&self) -> Option<&(dyn Error + 'static)> { + None + } + + /// Gets the `TypeId` of `self`. + #[doc(hidden)] + #[unstable( + feature = "error_type_id", + reason = "this is memory-unsafe to override in user code", + issue = "60784" + )] + fn type_id(&self, _: private::Internal) -> TypeId + where + Self: 'static, + { + TypeId::of::<Self>() + } + + /// ``` + /// if let Err(e) = "xc".parse::<u32>() { + /// // Print `e` itself, no need for description(). + /// eprintln!("Error: {e}"); + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[deprecated(since = "1.42.0", note = "use the Display impl or to_string()")] + fn description(&self) -> &str { + "description() is deprecated; use Display" + } + + #[stable(feature = "rust1", since = "1.0.0")] + #[deprecated( + since = "1.33.0", + note = "replaced by Error::source, which can support downcasting" + )] + #[allow(missing_docs)] + fn cause(&self) -> Option<&dyn Error> { + self.source() + } + + /// Provides type based access to context intended for error reports. + /// + /// Used in conjunction with [`Demand::provide_value`] and [`Demand::provide_ref`] to extract + /// references to member variables from `dyn Error` trait objects. + /// + /// # Example + /// + /// ```rust + /// #![feature(provide_any)] + /// #![feature(error_generic_member_access)] + /// use core::fmt; + /// use core::any::Demand; + /// + /// #[derive(Debug)] + /// struct MyBacktrace { + /// // ... + /// } + /// + /// impl MyBacktrace { + /// fn new() -> MyBacktrace { + /// // ... + /// # MyBacktrace {} + /// } + /// } + /// + /// #[derive(Debug)] + /// struct SourceError { + /// // ... + /// } + /// + /// impl fmt::Display for SourceError { + /// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + /// write!(f, "Example Source Error") + /// } + /// } + /// + /// impl std::error::Error for SourceError {} + /// + /// #[derive(Debug)] + /// struct Error { + /// source: SourceError, + /// backtrace: MyBacktrace, + /// } + /// + /// impl fmt::Display for Error { + /// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + /// write!(f, "Example Error") + /// } + /// } + /// + /// impl std::error::Error for Error { + /// fn provide<'a>(&'a self, demand: &mut Demand<'a>) { + /// demand + /// .provide_ref::<MyBacktrace>(&self.backtrace) + /// .provide_ref::<dyn std::error::Error + 'static>(&self.source); + /// } + /// } + /// + /// fn main() { + /// let backtrace = MyBacktrace::new(); + /// let source = SourceError {}; + /// let error = Error { source, backtrace }; + /// let dyn_error = &error as &dyn std::error::Error; + /// let backtrace_ref = dyn_error.request_ref::<MyBacktrace>().unwrap(); + /// + /// assert!(core::ptr::eq(&error.backtrace, backtrace_ref)); + /// } + /// ``` + #[unstable(feature = "error_generic_member_access", issue = "99301")] + #[allow(unused_variables)] + fn provide<'a>(&'a self, demand: &mut Demand<'a>) {} +} + +#[unstable(feature = "error_generic_member_access", issue = "99301")] +impl<E> Provider for E +where + E: Error + ?Sized, +{ + fn provide<'a>(&'a self, demand: &mut Demand<'a>) { + self.provide(demand) + } +} + +mod private { + // This is a hack to prevent `type_id` from being overridden by `Error` + // implementations, since that can enable unsound downcasting. + #[unstable(feature = "error_type_id", issue = "60784")] + #[derive(Debug)] + pub struct Internal; +} + +#[unstable(feature = "never_type", issue = "35121")] +impl Error for ! {} + +impl<'a> dyn Error + 'a { + /// Request a reference of type `T` as context about this error. + #[unstable(feature = "error_generic_member_access", issue = "99301")] + pub fn request_ref<T: ?Sized + 'static>(&'a self) -> Option<&'a T> { + core::any::request_ref(self) + } + + /// Request a value of type `T` as context about this error. + #[unstable(feature = "error_generic_member_access", issue = "99301")] + pub fn request_value<T: 'static>(&'a self) -> Option<T> { + core::any::request_value(self) + } +} + +// Copied from `any.rs`. +impl dyn Error + 'static { + /// Returns `true` if the inner type is the same as `T`. + #[stable(feature = "error_downcast", since = "1.3.0")] + #[inline] + pub fn is<T: Error + 'static>(&self) -> bool { + // Get `TypeId` of the type this function is instantiated with. + let t = TypeId::of::<T>(); + + // Get `TypeId` of the type in the trait object (`self`). + let concrete = self.type_id(private::Internal); + + // Compare both `TypeId`s on equality. + t == concrete + } + + /// Returns some reference to the inner value if it is of type `T`, or + /// `None` if it isn't. + #[stable(feature = "error_downcast", since = "1.3.0")] + #[inline] + pub fn downcast_ref<T: Error + 'static>(&self) -> Option<&T> { + if self.is::<T>() { + // SAFETY: `is` ensures this type cast is correct + unsafe { Some(&*(self as *const dyn Error as *const T)) } + } else { + None + } + } + + /// Returns some mutable reference to the inner value if it is of type `T`, or + /// `None` if it isn't. + #[stable(feature = "error_downcast", since = "1.3.0")] + #[inline] + pub fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T> { + if self.is::<T>() { + // SAFETY: `is` ensures this type cast is correct + unsafe { Some(&mut *(self as *mut dyn Error as *mut T)) } + } else { + None + } + } +} + +impl dyn Error + 'static + Send { + /// Forwards to the method defined on the type `dyn Error`. + #[stable(feature = "error_downcast", since = "1.3.0")] + #[inline] + pub fn is<T: Error + 'static>(&self) -> bool { + <dyn Error + 'static>::is::<T>(self) + } + + /// Forwards to the method defined on the type `dyn Error`. + #[stable(feature = "error_downcast", since = "1.3.0")] + #[inline] + pub fn downcast_ref<T: Error + 'static>(&self) -> Option<&T> { + <dyn Error + 'static>::downcast_ref::<T>(self) + } + + /// Forwards to the method defined on the type `dyn Error`. + #[stable(feature = "error_downcast", since = "1.3.0")] + #[inline] + pub fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T> { + <dyn Error + 'static>::downcast_mut::<T>(self) + } + + /// Request a reference of type `T` as context about this error. + #[unstable(feature = "error_generic_member_access", issue = "99301")] + pub fn request_ref<T: ?Sized + 'static>(&self) -> Option<&T> { + <dyn Error>::request_ref(self) + } + + /// Request a value of type `T` as context about this error. + #[unstable(feature = "error_generic_member_access", issue = "99301")] + pub fn request_value<T: 'static>(&self) -> Option<T> { + <dyn Error>::request_value(self) + } +} + +impl dyn Error + 'static + Send + Sync { + /// Forwards to the method defined on the type `dyn Error`. + #[stable(feature = "error_downcast", since = "1.3.0")] + #[inline] + pub fn is<T: Error + 'static>(&self) -> bool { + <dyn Error + 'static>::is::<T>(self) + } + + /// Forwards to the method defined on the type `dyn Error`. + #[stable(feature = "error_downcast", since = "1.3.0")] + #[inline] + pub fn downcast_ref<T: Error + 'static>(&self) -> Option<&T> { + <dyn Error + 'static>::downcast_ref::<T>(self) + } + + /// Forwards to the method defined on the type `dyn Error`. + #[stable(feature = "error_downcast", since = "1.3.0")] + #[inline] + pub fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T> { + <dyn Error + 'static>::downcast_mut::<T>(self) + } + + /// Request a reference of type `T` as context about this error. + #[unstable(feature = "error_generic_member_access", issue = "99301")] + pub fn request_ref<T: ?Sized + 'static>(&self) -> Option<&T> { + <dyn Error>::request_ref(self) + } + + /// Request a value of type `T` as context about this error. + #[unstable(feature = "error_generic_member_access", issue = "99301")] + pub fn request_value<T: 'static>(&self) -> Option<T> { + <dyn Error>::request_value(self) + } +} + +impl dyn Error { + /// Returns an iterator starting with the current error and continuing with + /// recursively calling [`Error::source`]. + /// + /// If you want to omit the current error and only use its sources, + /// use `skip(1)`. + /// + /// # Examples + /// + /// ``` + /// #![feature(error_iter)] + /// use std::error::Error; + /// use std::fmt; + /// + /// #[derive(Debug)] + /// struct A; + /// + /// #[derive(Debug)] + /// struct B(Option<Box<dyn Error + 'static>>); + /// + /// impl fmt::Display for A { + /// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + /// write!(f, "A") + /// } + /// } + /// + /// impl fmt::Display for B { + /// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + /// write!(f, "B") + /// } + /// } + /// + /// impl Error for A {} + /// + /// impl Error for B { + /// fn source(&self) -> Option<&(dyn Error + 'static)> { + /// self.0.as_ref().map(|e| e.as_ref()) + /// } + /// } + /// + /// let b = B(Some(Box::new(A))); + /// + /// // let err : Box<Error> = b.into(); // or + /// let err = &b as &(dyn Error); + /// + /// let mut iter = err.sources(); + /// + /// assert_eq!("B".to_string(), iter.next().unwrap().to_string()); + /// assert_eq!("A".to_string(), iter.next().unwrap().to_string()); + /// assert!(iter.next().is_none()); + /// assert!(iter.next().is_none()); + /// ``` + #[unstable(feature = "error_iter", issue = "58520")] + #[inline] + pub fn sources(&self) -> Source<'_> { + // You may think this method would be better in the Error trait, and you'd be right. + // Unfortunately that doesn't work, not because of the object safety rules but because we + // save a reference to self in Sources below as a trait object. If this method was + // declared in Error, then self would have the type &T where T is some concrete type which + // implements Error. We would need to coerce self to have type &dyn Error, but that requires + // that Self has a known size (i.e., Self: Sized). We can't put that bound on Error + // since that would forbid Error trait objects, and we can't put that bound on the method + // because that means the method can't be called on trait objects (we'd also need the + // 'static bound, but that isn't allowed because methods with bounds on Self other than + // Sized are not object-safe). Requiring an Unsize bound is not backwards compatible. + + Source { current: Some(self) } + } +} + +/// An iterator over an [`Error`] and its sources. +/// +/// If you want to omit the initial error and only process +/// its sources, use `skip(1)`. +#[unstable(feature = "error_iter", issue = "58520")] +#[derive(Clone, Debug)] +pub struct Source<'a> { + current: Option<&'a (dyn Error + 'static)>, +} + +#[unstable(feature = "error_iter", issue = "58520")] +impl<'a> Iterator for Source<'a> { + type Item = &'a (dyn Error + 'static); + + fn next(&mut self) -> Option<Self::Item> { + let current = self.current; + self.current = self.current.and_then(Error::source); + current + } +} + +#[stable(feature = "error_by_ref", since = "1.51.0")] +impl<'a, T: Error + ?Sized> Error for &'a T { + #[allow(deprecated, deprecated_in_future)] + fn description(&self) -> &str { + Error::description(&**self) + } + + #[allow(deprecated)] + fn cause(&self) -> Option<&dyn Error> { + Error::cause(&**self) + } + + fn source(&self) -> Option<&(dyn Error + 'static)> { + Error::source(&**self) + } + + fn provide<'b>(&'b self, demand: &mut Demand<'b>) { + Error::provide(&**self, demand); + } +} + +#[stable(feature = "fmt_error", since = "1.11.0")] +impl Error for crate::fmt::Error { + #[allow(deprecated)] + fn description(&self) -> &str { + "an error occurred when formatting an argument" + } +} + +#[stable(feature = "try_borrow", since = "1.13.0")] +impl Error for crate::cell::BorrowError { + #[allow(deprecated)] + fn description(&self) -> &str { + "already mutably borrowed" + } +} + +#[stable(feature = "try_borrow", since = "1.13.0")] +impl Error for crate::cell::BorrowMutError { + #[allow(deprecated)] + fn description(&self) -> &str { + "already borrowed" + } +} + +#[stable(feature = "try_from", since = "1.34.0")] +impl Error for crate::char::CharTryFromError { + #[allow(deprecated)] + fn description(&self) -> &str { + "converted integer out of range for `char`" + } +} + +#[stable(feature = "char_from_str", since = "1.20.0")] +impl Error for crate::char::ParseCharError { + #[allow(deprecated)] + fn description(&self) -> &str { + self.__description() + } +} + +#[stable(feature = "duration_checked_float", since = "1.66.0")] +impl Error for crate::time::TryFromFloatSecsError {} + +#[stable(feature = "frombyteswithnulerror_impls", since = "1.17.0")] +impl Error for crate::ffi::FromBytesWithNulError { + #[allow(deprecated)] + fn description(&self) -> &str { + self.__description() + } +} + +#[unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")] +impl Error for crate::ffi::FromBytesUntilNulError {} diff --git a/library/core/src/ffi/c_double.md b/library/core/src/ffi/c_double.md index 57f453482..d49e29b6e 100644 --- a/library/core/src/ffi/c_double.md +++ b/library/core/src/ffi/c_double.md @@ -1,6 +1,6 @@ Equivalent to C's `double` type. -This type will almost always be [`f64`], which is guaranteed to be an [IEEE-754 double-precision float] in Rust. That said, the standard technically only guarantees that it be a floating-point number with at least the precision of a [`float`], and it may be `f32` or something entirely different from the IEEE-754 standard. +This type will almost always be [`f64`], which is guaranteed to be an [IEEE 754 double-precision float] in Rust. That said, the standard technically only guarantees that it be a floating-point number with at least the precision of a [`float`], and it may be `f32` or something entirely different from the IEEE-754 standard. -[IEEE-754 double-precision float]: https://en.wikipedia.org/wiki/IEEE_754 +[IEEE 754 double-precision float]: https://en.wikipedia.org/wiki/IEEE_754 [`float`]: c_float diff --git a/library/core/src/ffi/c_float.md b/library/core/src/ffi/c_float.md index 61e2abc05..36374ef43 100644 --- a/library/core/src/ffi/c_float.md +++ b/library/core/src/ffi/c_float.md @@ -1,5 +1,5 @@ Equivalent to C's `float` type. -This type will almost always be [`f32`], which is guaranteed to be an [IEEE-754 single-precision float] in Rust. That said, the standard technically only guarantees that it be a floating-point number, and it may have less precision than `f32` or not follow the IEEE-754 standard at all. +This type will almost always be [`f32`], which is guaranteed to be an [IEEE 754 single-precision float] in Rust. That said, the standard technically only guarantees that it be a floating-point number, and it may have less precision than `f32` or not follow the IEEE-754 standard at all. -[IEEE-754 single-precision float]: https://en.wikipedia.org/wiki/IEEE_754 +[IEEE 754 single-precision float]: https://en.wikipedia.org/wiki/IEEE_754 diff --git a/library/core/src/ffi/c_str.rs b/library/core/src/ffi/c_str.rs index 82e63a7fe..8923f548a 100644 --- a/library/core/src/ffi/c_str.rs +++ b/library/core/src/ffi/c_str.rs @@ -1,7 +1,6 @@ -use crate::ascii; use crate::cmp::Ordering; use crate::ffi::c_char; -use crate::fmt::{self, Write}; +use crate::fmt; use crate::intrinsics; use crate::ops; use crate::slice; @@ -121,10 +120,10 @@ enum FromBytesWithNulErrorKind { } impl FromBytesWithNulError { - fn interior_nul(pos: usize) -> FromBytesWithNulError { + const fn interior_nul(pos: usize) -> FromBytesWithNulError { FromBytesWithNulError { kind: FromBytesWithNulErrorKind::InteriorNul(pos) } } - fn not_nul_terminated() -> FromBytesWithNulError { + const fn not_nul_terminated() -> FromBytesWithNulError { FromBytesWithNulError { kind: FromBytesWithNulErrorKind::NotNulTerminated } } @@ -161,11 +160,7 @@ impl fmt::Display for FromBytesUntilNulError { #[stable(feature = "cstr_debug", since = "1.3.0")] impl fmt::Debug for CStr { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - write!(f, "\"")?; - for byte in self.to_bytes().iter().flat_map(|&b| ascii::escape_default(b)) { - f.write_char(byte as char)?; - } - write!(f, "\"") + write!(f, "\"{}\"", self.to_bytes().escape_ascii()) } } @@ -226,9 +221,7 @@ impl CStr { /// # Examples /// /// ```ignore (extern-declaration) - /// # fn main() { - /// use std::ffi::CStr; - /// use std::os::raw::c_char; + /// use std::ffi::{c_char, CStr}; /// /// extern "C" { /// fn my_string() -> *const c_char; @@ -238,14 +231,26 @@ impl CStr { /// let slice = CStr::from_ptr(my_string()); /// println!("string returned: {}", slice.to_str().unwrap()); /// } - /// # } + /// ``` + /// + /// ``` + /// #![feature(const_cstr_methods)] + /// + /// use std::ffi::{c_char, CStr}; + /// + /// const HELLO_PTR: *const c_char = { + /// const BYTES: &[u8] = b"Hello, world!\0"; + /// BYTES.as_ptr().cast() + /// }; + /// const HELLO: &CStr = unsafe { CStr::from_ptr(HELLO_PTR) }; /// ``` /// /// [valid]: core::ptr#safety #[inline] #[must_use] #[stable(feature = "rust1", since = "1.0.0")] - pub unsafe fn from_ptr<'a>(ptr: *const c_char) -> &'a CStr { + #[rustc_const_unstable(feature = "const_cstr_methods", issue = "101719")] + pub const unsafe fn from_ptr<'a>(ptr: *const c_char) -> &'a CStr { // SAFETY: The caller has provided a pointer that points to a valid C // string with a NUL terminator of size less than `isize::MAX`, whose // content remain valid and doesn't change for the lifetime of the @@ -257,13 +262,29 @@ impl CStr { // // The cast from c_char to u8 is ok because a c_char is always one byte. unsafe { - extern "C" { - /// Provided by libc or compiler_builtins. - fn strlen(s: *const c_char) -> usize; + const fn strlen_ct(s: *const c_char) -> usize { + let mut len = 0; + + // SAFETY: Outer caller has provided a pointer to a valid C string. + while unsafe { *s.add(len) } != 0 { + len += 1; + } + + len } - let len = strlen(ptr); - let ptr = ptr as *const u8; - CStr::from_bytes_with_nul_unchecked(slice::from_raw_parts(ptr, len as usize + 1)) + + fn strlen_rt(s: *const c_char) -> usize { + extern "C" { + /// Provided by libc or compiler_builtins. + fn strlen(s: *const c_char) -> usize; + } + + // SAFETY: Outer caller has provided a pointer to a valid C string. + unsafe { strlen(s) } + } + + let len = intrinsics::const_eval_select((ptr,), strlen_ct, strlen_rt); + Self::from_bytes_with_nul_unchecked(slice::from_raw_parts(ptr.cast(), len + 1)) } } @@ -299,7 +320,8 @@ impl CStr { /// ``` /// #[unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")] - pub fn from_bytes_until_nul(bytes: &[u8]) -> Result<&CStr, FromBytesUntilNulError> { + #[rustc_const_unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")] + pub const fn from_bytes_until_nul(bytes: &[u8]) -> Result<&CStr, FromBytesUntilNulError> { let nul_pos = memchr::memchr(0, bytes); match nul_pos { Some(nul_pos) => { @@ -348,7 +370,8 @@ impl CStr { /// assert!(cstr.is_err()); /// ``` #[stable(feature = "cstr_from_bytes", since = "1.10.0")] - pub fn from_bytes_with_nul(bytes: &[u8]) -> Result<&Self, FromBytesWithNulError> { + #[rustc_const_unstable(feature = "const_cstr_methods", issue = "101719")] + pub const fn from_bytes_with_nul(bytes: &[u8]) -> Result<&Self, FromBytesWithNulError> { let nul_pos = memchr::memchr(0, bytes); match nul_pos { Some(nul_pos) if nul_pos + 1 == bytes.len() => { @@ -387,6 +410,7 @@ impl CStr { #[rustc_const_stable(feature = "const_cstr_unchecked", since = "1.59.0")] #[rustc_allow_const_fn_unstable(const_eval_select)] pub const unsafe fn from_bytes_with_nul_unchecked(bytes: &[u8]) -> &CStr { + #[inline] fn rt_impl(bytes: &[u8]) -> &CStr { // Chance at catching some UB at runtime with debug builds. debug_assert!(!bytes.is_empty() && bytes[bytes.len() - 1] == 0); @@ -476,6 +500,34 @@ impl CStr { self.inner.as_ptr() } + /// Returns `true` if `self.to_bytes()` has a length of 0. + /// + /// # Examples + /// + /// ``` + /// #![feature(cstr_is_empty)] + /// + /// use std::ffi::CStr; + /// # use std::ffi::FromBytesWithNulError; + /// + /// # fn main() { test().unwrap(); } + /// # fn test() -> Result<(), FromBytesWithNulError> { + /// let cstr = CStr::from_bytes_with_nul(b"foo\0")?; + /// assert!(!cstr.is_empty()); + /// + /// let empty_cstr = CStr::from_bytes_with_nul(b"\0")?; + /// assert!(empty_cstr.is_empty()); + /// # Ok(()) + /// # } + /// ``` + #[inline] + #[unstable(feature = "cstr_is_empty", issue = "102444")] + pub const fn is_empty(&self) -> bool { + // SAFETY: We know there is at least one byte; for empty strings it + // is the NUL terminator. + (unsafe { self.inner.get_unchecked(0) }) == &0 + } + /// Converts this C string to a byte slice. /// /// The returned slice will **not** contain the trailing nul terminator that this C @@ -497,7 +549,8 @@ impl CStr { #[must_use = "this returns the result of the operation, \ without modifying the original"] #[stable(feature = "rust1", since = "1.0.0")] - pub fn to_bytes(&self) -> &[u8] { + #[rustc_const_unstable(feature = "const_cstr_methods", issue = "101719")] + pub const fn to_bytes(&self) -> &[u8] { let bytes = self.to_bytes_with_nul(); // SAFETY: to_bytes_with_nul returns slice with length at least 1 unsafe { bytes.get_unchecked(..bytes.len() - 1) } @@ -524,7 +577,8 @@ impl CStr { #[must_use = "this returns the result of the operation, \ without modifying the original"] #[stable(feature = "rust1", since = "1.0.0")] - pub fn to_bytes_with_nul(&self) -> &[u8] { + #[rustc_const_unstable(feature = "const_cstr_methods", issue = "101719")] + pub const fn to_bytes_with_nul(&self) -> &[u8] { // SAFETY: Transmuting a slice of `c_char`s to a slice of `u8`s // is safe on all supported targets. unsafe { &*(&self.inner as *const [c_char] as *const [u8]) } @@ -547,7 +601,8 @@ impl CStr { /// assert_eq!(cstr.to_str(), Ok("foo")); /// ``` #[stable(feature = "cstr_to_str", since = "1.4.0")] - pub fn to_str(&self) -> Result<&str, str::Utf8Error> { + #[rustc_const_unstable(feature = "const_cstr_methods", issue = "101719")] + pub const fn to_str(&self) -> Result<&str, str::Utf8Error> { // N.B., when `CStr` is changed to perform the length check in `.to_bytes()` // instead of in `from_ptr()`, it may be worth considering if this should // be rewritten to do the UTF-8 check inline with the length calculation diff --git a/library/core/src/fmt/builders.rs b/library/core/src/fmt/builders.rs index 32d1a4e55..7da49b04a 100644 --- a/library/core/src/fmt/builders.rs +++ b/library/core/src/fmt/builders.rs @@ -28,24 +28,14 @@ impl<'buf, 'state> PadAdapter<'buf, 'state> { } impl fmt::Write for PadAdapter<'_, '_> { - fn write_str(&mut self, mut s: &str) -> fmt::Result { - while !s.is_empty() { + fn write_str(&mut self, s: &str) -> fmt::Result { + for s in s.split_inclusive('\n') { if self.state.on_newline { self.buf.write_str(" ")?; } - let split = match s.find('\n') { - Some(pos) => { - self.state.on_newline = true; - pos + 1 - } - None => { - self.state.on_newline = false; - s.len() - } - }; - self.buf.write_str(&s[..split])?; - s = &s[split..]; + self.state.on_newline = s.ends_with('\n'); + self.buf.write_str(s)?; } Ok(()) diff --git a/library/core/src/fmt/mod.rs b/library/core/src/fmt/mod.rs index 372141e09..c8d285505 100644 --- a/library/core/src/fmt/mod.rs +++ b/library/core/src/fmt/mod.rs @@ -119,6 +119,10 @@ pub trait Write { /// /// This function will return an instance of [`Error`] on error. /// + /// The purpose of std::fmt::Error is to abort the formatting operation when the underlying + /// destination encounters some error preventing it from accepting more text; it should + /// generally be propagated rather than handled, at least when implementing formatting traits. + /// /// # Examples /// /// ``` @@ -705,12 +709,19 @@ pub use macros::Debug; /// Format trait for an empty format, `{}`. /// +/// Implementing this trait for a type will automatically implement the +/// [`ToString`][tostring] trait for the type, allowing the usage +/// of the [`.to_string()`][tostring_function] method. Prefer implementing +/// the `Display` trait for a type, rather than [`ToString`][tostring]. +/// /// `Display` is similar to [`Debug`], but `Display` is for user-facing /// output, and so cannot be derived. /// /// For more information on formatters, see [the module-level documentation][module]. /// /// [module]: ../../std/fmt/index.html +/// [tostring]: ../../std/string/trait.ToString.html +/// [tostring_function]: ../../std/string/trait.ToString.html#tymethod.to_string /// /// # Examples /// @@ -1815,7 +1826,7 @@ impl<'a> Formatter<'a> { /// write!(formatter, /// "Foo({}{})", /// if self.0 < 0 { '-' } else { '+' }, - /// self.0) + /// self.0.abs()) /// } else { /// write!(formatter, "Foo({})", self.0) /// } @@ -1823,6 +1834,7 @@ impl<'a> Formatter<'a> { /// } /// /// assert_eq!(&format!("{:+}", Foo(23)), "Foo(+23)"); + /// assert_eq!(&format!("{:+}", Foo(-23)), "Foo(-23)"); /// assert_eq!(&format!("{}", Foo(23)), "Foo(23)"); /// ``` #[must_use] @@ -2562,7 +2574,7 @@ macro_rules! tuple { macro_rules! maybe_tuple_doc { ($a:ident @ #[$meta:meta] $item:item) => { - #[cfg_attr(not(bootstrap), doc(fake_variadic))] + #[doc(fake_variadic)] #[doc = "This trait is implemented for tuples up to twelve items long."] #[$meta] $item @@ -2598,7 +2610,7 @@ impl Debug for () { #[stable(feature = "rust1", since = "1.0.0")] impl<T: ?Sized> Debug for PhantomData<T> { fn fmt(&self, f: &mut Formatter<'_>) -> Result { - f.debug_struct("PhantomData").finish() + write!(f, "PhantomData<{}>", crate::any::type_name::<T>()) } } diff --git a/library/core/src/fmt/num.rs b/library/core/src/fmt/num.rs index 25789d37c..d8365ae9b 100644 --- a/library/core/src/fmt/num.rs +++ b/library/core/src/fmt/num.rs @@ -211,7 +211,7 @@ macro_rules! impl_Display { fn $name(mut n: $u, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::Result { // 2^128 is about 3*10^38, so 39 gives an extra byte of space let mut buf = [MaybeUninit::<u8>::uninit(); 39]; - let mut curr = buf.len() as isize; + let mut curr = buf.len(); let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf); let lut_ptr = DEC_DIGITS_LUT.as_ptr(); @@ -228,7 +228,7 @@ macro_rules! impl_Display { // eagerly decode 4 characters at a time while n >= 10000 { - let rem = (n % 10000) as isize; + let rem = (n % 10000) as usize; n /= 10000; let d1 = (rem / 100) << 1; @@ -238,29 +238,29 @@ macro_rules! impl_Display { // We are allowed to copy to `buf_ptr[curr..curr + 3]` here since // otherwise `curr < 0`. But then `n` was originally at least `10000^10` // which is `10^40 > 2^128 > n`. - ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2); - ptr::copy_nonoverlapping(lut_ptr.offset(d2), buf_ptr.offset(curr + 2), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d1), buf_ptr.add(curr), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d2), buf_ptr.add(curr + 2), 2); } // if we reach here numbers are <= 9999, so at most 4 chars long - let mut n = n as isize; // possibly reduce 64bit math + let mut n = n as usize; // possibly reduce 64bit math // decode 2 more chars, if > 2 chars if n >= 100 { let d1 = (n % 100) << 1; n /= 100; curr -= 2; - ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d1), buf_ptr.add(curr), 2); } // decode last 1 or 2 chars if n < 10 { curr -= 1; - *buf_ptr.offset(curr) = (n as u8) + b'0'; + *buf_ptr.add(curr) = (n as u8) + b'0'; } else { let d1 = n << 1; curr -= 2; - ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d1), buf_ptr.add(curr), 2); } } @@ -268,7 +268,7 @@ macro_rules! impl_Display { // UTF-8 since `DEC_DIGITS_LUT` is let buf_slice = unsafe { str::from_utf8_unchecked( - slice::from_raw_parts(buf_ptr.offset(curr), buf.len() - curr as usize)) + slice::from_raw_parts(buf_ptr.add(curr), buf.len() - curr)) }; f.pad_integral(is_nonnegative, "", buf_slice) } @@ -339,18 +339,18 @@ macro_rules! impl_Exp { // Since `curr` always decreases by the number of digits copied, this means // that `curr >= 0`. let mut buf = [MaybeUninit::<u8>::uninit(); 40]; - let mut curr = buf.len() as isize; //index for buf + let mut curr = buf.len(); //index for buf let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf); let lut_ptr = DEC_DIGITS_LUT.as_ptr(); // decode 2 chars at a time while n >= 100 { - let d1 = ((n % 100) as isize) << 1; + let d1 = ((n % 100) as usize) << 1; curr -= 2; // SAFETY: `d1 <= 198`, so we can copy from `lut_ptr[d1..d1 + 2]` since // `DEC_DIGITS_LUT` has a length of 200. unsafe { - ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d1), buf_ptr.add(curr), 2); } n /= 100; exponent += 2; @@ -362,7 +362,7 @@ macro_rules! impl_Exp { curr -= 1; // SAFETY: Safe since `40 > curr >= 0` (see comment) unsafe { - *buf_ptr.offset(curr) = (n as u8 % 10_u8) + b'0'; + *buf_ptr.add(curr) = (n as u8 % 10_u8) + b'0'; } n /= 10; exponent += 1; @@ -372,7 +372,7 @@ macro_rules! impl_Exp { curr -= 1; // SAFETY: Safe since `40 > curr >= 0` unsafe { - *buf_ptr.offset(curr) = b'.'; + *buf_ptr.add(curr) = b'.'; } } @@ -380,10 +380,10 @@ macro_rules! impl_Exp { let buf_slice = unsafe { // decode last character curr -= 1; - *buf_ptr.offset(curr) = (n as u8) + b'0'; + *buf_ptr.add(curr) = (n as u8) + b'0'; let len = buf.len() - curr as usize; - slice::from_raw_parts(buf_ptr.offset(curr), len) + slice::from_raw_parts(buf_ptr.add(curr), len) }; // stores 'e' (or 'E') and the up to 2-digit exponent @@ -392,13 +392,13 @@ macro_rules! impl_Exp { // SAFETY: In either case, `exp_buf` is written within bounds and `exp_ptr[..len]` // is contained within `exp_buf` since `len <= 3`. let exp_slice = unsafe { - *exp_ptr.offset(0) = if upper { b'E' } else { b'e' }; + *exp_ptr.add(0) = if upper { b'E' } else { b'e' }; let len = if exponent < 10 { - *exp_ptr.offset(1) = (exponent as u8) + b'0'; + *exp_ptr.add(1) = (exponent as u8) + b'0'; 2 } else { let off = exponent << 1; - ptr::copy_nonoverlapping(lut_ptr.offset(off), exp_ptr.offset(1), 2); + ptr::copy_nonoverlapping(lut_ptr.add(off), exp_ptr.add(1), 2); 3 }; slice::from_raw_parts(exp_ptr, len) @@ -479,7 +479,7 @@ mod imp { impl_Exp!(i128, u128 as u128 via to_u128 named exp_u128); /// Helper function for writing a u64 into `buf` going from last to first, with `curr`. -fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], curr: &mut isize) { +fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], curr: &mut usize) { let buf_ptr = MaybeUninit::slice_as_mut_ptr(buf); let lut_ptr = DEC_DIGITS_LUT.as_ptr(); assert!(*curr > 19); @@ -505,14 +505,14 @@ fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], cu *curr -= 16; - ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr + 0), 2); - ptr::copy_nonoverlapping(lut_ptr.offset(d2 as isize), buf_ptr.offset(*curr + 2), 2); - ptr::copy_nonoverlapping(lut_ptr.offset(d3 as isize), buf_ptr.offset(*curr + 4), 2); - ptr::copy_nonoverlapping(lut_ptr.offset(d4 as isize), buf_ptr.offset(*curr + 6), 2); - ptr::copy_nonoverlapping(lut_ptr.offset(d5 as isize), buf_ptr.offset(*curr + 8), 2); - ptr::copy_nonoverlapping(lut_ptr.offset(d6 as isize), buf_ptr.offset(*curr + 10), 2); - ptr::copy_nonoverlapping(lut_ptr.offset(d7 as isize), buf_ptr.offset(*curr + 12), 2); - ptr::copy_nonoverlapping(lut_ptr.offset(d8 as isize), buf_ptr.offset(*curr + 14), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d1 as usize), buf_ptr.add(*curr + 0), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d2 as usize), buf_ptr.add(*curr + 2), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d3 as usize), buf_ptr.add(*curr + 4), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d4 as usize), buf_ptr.add(*curr + 6), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d5 as usize), buf_ptr.add(*curr + 8), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d6 as usize), buf_ptr.add(*curr + 10), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d7 as usize), buf_ptr.add(*curr + 12), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d8 as usize), buf_ptr.add(*curr + 14), 2); } if n >= 1e8 as u64 { let to_parse = n % 1e8 as u64; @@ -525,10 +525,10 @@ fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], cu let d4 = ((to_parse / 1e0 as u64) % 100) << 1; *curr -= 8; - ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr + 0), 2); - ptr::copy_nonoverlapping(lut_ptr.offset(d2 as isize), buf_ptr.offset(*curr + 2), 2); - ptr::copy_nonoverlapping(lut_ptr.offset(d3 as isize), buf_ptr.offset(*curr + 4), 2); - ptr::copy_nonoverlapping(lut_ptr.offset(d4 as isize), buf_ptr.offset(*curr + 6), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d1 as usize), buf_ptr.add(*curr + 0), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d2 as usize), buf_ptr.add(*curr + 2), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d3 as usize), buf_ptr.add(*curr + 4), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d4 as usize), buf_ptr.add(*curr + 6), 2); } // `n` < 1e8 < (1 << 32) let mut n = n as u32; @@ -540,8 +540,8 @@ fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], cu let d2 = (to_parse % 100) << 1; *curr -= 4; - ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr + 0), 2); - ptr::copy_nonoverlapping(lut_ptr.offset(d2 as isize), buf_ptr.offset(*curr + 2), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d1 as usize), buf_ptr.add(*curr + 0), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d2 as usize), buf_ptr.add(*curr + 2), 2); } // `n` < 1e4 < (1 << 16) @@ -550,17 +550,17 @@ fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], cu let d1 = (n % 100) << 1; n /= 100; *curr -= 2; - ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d1 as usize), buf_ptr.add(*curr), 2); } // decode last 1 or 2 chars if n < 10 { *curr -= 1; - *buf_ptr.offset(*curr) = (n as u8) + b'0'; + *buf_ptr.add(*curr) = (n as u8) + b'0'; } else { let d1 = n << 1; *curr -= 2; - ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr), 2); + ptr::copy_nonoverlapping(lut_ptr.add(d1 as usize), buf_ptr.add(*curr), 2); } } } @@ -593,21 +593,21 @@ impl fmt::Display for i128 { fn fmt_u128(n: u128, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::Result { // 2^128 is about 3*10^38, so 39 gives an extra byte of space let mut buf = [MaybeUninit::<u8>::uninit(); 39]; - let mut curr = buf.len() as isize; + let mut curr = buf.len(); let (n, rem) = udiv_1e19(n); parse_u64_into(rem, &mut buf, &mut curr); if n != 0 { // 0 pad up to point - let target = (buf.len() - 19) as isize; + let target = buf.len() - 19; // SAFETY: Guaranteed that we wrote at most 19 bytes, and there must be space // remaining since it has length 39 unsafe { ptr::write_bytes( - MaybeUninit::slice_as_mut_ptr(&mut buf).offset(target), + MaybeUninit::slice_as_mut_ptr(&mut buf).add(target), b'0', - (curr - target) as usize, + curr - target, ); } curr = target; @@ -616,16 +616,16 @@ fn fmt_u128(n: u128, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::R parse_u64_into(rem, &mut buf, &mut curr); // Should this following branch be annotated with unlikely? if n != 0 { - let target = (buf.len() - 38) as isize; + let target = buf.len() - 38; // The raw `buf_ptr` pointer is only valid until `buf` is used the next time, // buf `buf` is not used in this scope so we are good. let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf); // SAFETY: At this point we wrote at most 38 bytes, pad up to that point, // There can only be at most 1 digit remaining. unsafe { - ptr::write_bytes(buf_ptr.offset(target), b'0', (curr - target) as usize); + ptr::write_bytes(buf_ptr.add(target), b'0', curr - target); curr = target - 1; - *buf_ptr.offset(curr) = (n as u8) + b'0'; + *buf_ptr.add(curr) = (n as u8) + b'0'; } } } @@ -634,8 +634,8 @@ fn fmt_u128(n: u128, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::R // UTF-8 since `DEC_DIGITS_LUT` is let buf_slice = unsafe { str::from_utf8_unchecked(slice::from_raw_parts( - MaybeUninit::slice_as_mut_ptr(&mut buf).offset(curr), - buf.len() - curr as usize, + MaybeUninit::slice_as_mut_ptr(&mut buf).add(curr), + buf.len() - curr, )) }; f.pad_integral(is_nonnegative, "", buf_slice) diff --git a/library/core/src/future/poll_fn.rs b/library/core/src/future/poll_fn.rs index db2a52332..90cb79739 100644 --- a/library/core/src/future/poll_fn.rs +++ b/library/core/src/future/poll_fn.rs @@ -5,7 +5,9 @@ use crate::task::{Context, Poll}; /// Creates a future that wraps a function returning [`Poll`]. /// -/// Polling the future delegates to the wrapped function. +/// Polling the future delegates to the wrapped function. If the returned future is pinned, then the +/// captured environment of the wrapped function is also pinned in-place, so as long as the closure +/// does not move out of its captures it can soundly create pinned references to them. /// /// # Examples /// @@ -41,7 +43,7 @@ pub struct PollFn<F> { } #[stable(feature = "future_poll_fn", since = "1.64.0")] -impl<F> Unpin for PollFn<F> {} +impl<F: Unpin> Unpin for PollFn<F> {} #[stable(feature = "future_poll_fn", since = "1.64.0")] impl<F> fmt::Debug for PollFn<F> { @@ -57,7 +59,8 @@ where { type Output = T; - fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> { - (&mut self.f)(cx) + fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> { + // SAFETY: We are not moving out of the pinned field. + (unsafe { &mut self.get_unchecked_mut().f })(cx) } } diff --git a/library/core/src/future/ready.rs b/library/core/src/future/ready.rs index 48f20f90a..a07b63fb6 100644 --- a/library/core/src/future/ready.rs +++ b/library/core/src/future/ready.rs @@ -24,6 +24,30 @@ impl<T> Future for Ready<T> { } } +impl<T> Ready<T> { + /// Consumes the `Ready`, returning the wrapped value. + /// + /// # Panics + /// + /// Will panic if this [`Ready`] was already polled to completion. + /// + /// # Examples + /// + /// ``` + /// #![feature(ready_into_inner)] + /// use std::future; + /// + /// let a = future::ready(1); + /// assert_eq!(a.into_inner(), 1); + /// ``` + #[unstable(feature = "ready_into_inner", issue = "101196")] + #[must_use] + #[inline] + pub fn into_inner(self) -> T { + self.0.expect("Called `into_inner()` on `Ready` after completion") + } +} + /// Creates a future that is immediately ready with a value. /// /// Futures created through this function are functionally similar to those diff --git a/library/core/src/hash/mod.rs b/library/core/src/hash/mod.rs index 5974562ac..aa13435e6 100644 --- a/library/core/src/hash/mod.rs +++ b/library/core/src/hash/mod.rs @@ -900,7 +900,7 @@ mod impls { macro_rules! maybe_tuple_doc { ($a:ident @ #[$meta:meta] $item:item) => { - #[cfg_attr(not(bootstrap), doc(fake_variadic))] + #[doc(fake_variadic)] #[doc = "This trait is implemented for tuples up to twelve items long."] #[$meta] $item diff --git a/library/core/src/hint.rs b/library/core/src/hint.rs index 81b6d5737..c53175ba4 100644 --- a/library/core/src/hint.rs +++ b/library/core/src/hint.rs @@ -31,7 +31,7 @@ use crate::intrinsics; /// /// `unreachable_unchecked()` can be used in situations where the compiler /// can't prove invariants that were previously established. Such situations -/// have a higher chance of occuring if those invariants are upheld by +/// have a higher chance of occurring if those invariants are upheld by /// external code that the compiler can't analyze. /// ``` /// fn prepare_inputs(divisors: &mut Vec<u32>) { @@ -100,7 +100,10 @@ use crate::intrinsics; pub const unsafe fn unreachable_unchecked() -> ! { // SAFETY: the safety contract for `intrinsics::unreachable` must // be upheld by the caller. - unsafe { intrinsics::unreachable() } + unsafe { + intrinsics::assert_unsafe_precondition!("hint::unreachable_unchecked must never be reached", () => false); + intrinsics::unreachable() + } } /// Emits a machine instruction to signal the processor that it is running in @@ -160,19 +163,16 @@ pub const unsafe fn unreachable_unchecked() -> ! { #[inline] #[stable(feature = "renamed_spin_loop", since = "1.49.0")] pub fn spin_loop() { - #[cfg(all(any(target_arch = "x86", target_arch = "x86_64"), target_feature = "sse2"))] + #[cfg(target_arch = "x86")] { - #[cfg(target_arch = "x86")] - { - // SAFETY: the `cfg` attr ensures that we only execute this on x86 targets. - unsafe { crate::arch::x86::_mm_pause() }; - } + // SAFETY: the `cfg` attr ensures that we only execute this on x86 targets. + unsafe { crate::arch::x86::_mm_pause() }; + } - #[cfg(target_arch = "x86_64")] - { - // SAFETY: the `cfg` attr ensures that we only execute this on x86_64 targets. - unsafe { crate::arch::x86_64::_mm_pause() }; - } + #[cfg(target_arch = "x86_64")] + { + // SAFETY: the `cfg` attr ensures that we only execute this on x86_64 targets. + unsafe { crate::arch::x86_64::_mm_pause() }; } // RISC-V platform spin loop hint implementation @@ -220,7 +220,7 @@ pub fn spin_loop() { /// /// [`std::convert::identity`]: crate::convert::identity #[inline] -#[unstable(feature = "bench_black_box", issue = "64102")] +#[stable(feature = "bench_black_box", since = "1.66.0")] #[rustc_const_unstable(feature = "const_black_box", issue = "none")] pub const fn black_box<T>(dummy: T) -> T { crate::intrinsics::black_box(dummy) diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs index cabc5017f..1dc79afe8 100644 --- a/library/core/src/intrinsics.rs +++ b/library/core/src/intrinsics.rs @@ -54,7 +54,7 @@ )] #![allow(missing_docs)] -use crate::marker::{Destruct, DiscriminantKind}; +use crate::marker::DiscriminantKind; use crate::mem; // These imports are used for simplifying intra-doc links @@ -63,7 +63,7 @@ use crate::mem; use crate::sync::atomic::{self, AtomicBool, AtomicI32, AtomicIsize, AtomicU32, Ordering}; #[stable(feature = "drop_in_place", since = "1.8.0")] -#[cfg_attr(not(bootstrap), rustc_allowed_through_unstable_modules)] +#[rustc_allowed_through_unstable_modules] #[deprecated(note = "no longer an intrinsic - use `ptr::drop_in_place` directly", since = "1.52.0")] #[inline] pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) { @@ -71,214 +71,6 @@ pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) { unsafe { crate::ptr::drop_in_place(to_drop) } } -// These have been renamed. -#[cfg(bootstrap)] -extern "rust-intrinsic" { - pub fn atomic_cxchg<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchg_acq<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchg_rel<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchg_acqrel<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchg_relaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchg_failrelaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchg_failacq<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchg_acq_failrelaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchg_acqrel_failrelaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchgweak<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchgweak_acq<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchgweak_rel<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchgweak_acqrel<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchgweak_relaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchgweak_failrelaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchgweak_failacq<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchgweak_acq_failrelaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_cxchgweak_acqrel_failrelaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); - pub fn atomic_load<T: Copy>(src: *const T) -> T; - pub fn atomic_load_acq<T: Copy>(src: *const T) -> T; - pub fn atomic_load_relaxed<T: Copy>(src: *const T) -> T; - pub fn atomic_load_unordered<T: Copy>(src: *const T) -> T; - pub fn atomic_store<T: Copy>(dst: *mut T, val: T); - pub fn atomic_store_rel<T: Copy>(dst: *mut T, val: T); - pub fn atomic_store_relaxed<T: Copy>(dst: *mut T, val: T); - pub fn atomic_store_unordered<T: Copy>(dst: *mut T, val: T); - pub fn atomic_xchg<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xchg_acq<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xchg_rel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xchg_acqrel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xchg_relaxed<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xadd<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xadd_acq<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xadd_rel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xadd_acqrel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xadd_relaxed<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xsub<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xsub_acq<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xsub_rel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xsub_acqrel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xsub_relaxed<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_and<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_and_acq<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_and_rel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_and_acqrel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_and_relaxed<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_nand<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_nand_acq<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_nand_rel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_nand_acqrel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_nand_relaxed<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_or<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_or_acq<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_or_rel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_or_acqrel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_or_relaxed<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xor<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xor_acq<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xor_rel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xor_acqrel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_xor_relaxed<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_max<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_max_acq<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_max_rel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_max_acqrel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_max_relaxed<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_min<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_min_acq<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_min_rel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_min_acqrel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_min_relaxed<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_umin<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_umin_acq<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_umin_rel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_umin_acqrel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_umin_relaxed<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_umax<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_umax_acq<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_umax_rel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_umax_acqrel<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_umax_relaxed<T: Copy>(dst: *mut T, src: T) -> T; - pub fn atomic_fence(); - pub fn atomic_fence_acq(); - pub fn atomic_fence_rel(); - pub fn atomic_fence_acqrel(); - pub fn atomic_singlethreadfence(); - pub fn atomic_singlethreadfence_acq(); - pub fn atomic_singlethreadfence_rel(); - pub fn atomic_singlethreadfence_acqrel(); -} - -// These have been renamed. -#[cfg(bootstrap)] -mod atomics { - pub use super::atomic_cxchg as atomic_cxchg_seqcst_seqcst; - pub use super::atomic_cxchg_acq as atomic_cxchg_acquire_acquire; - pub use super::atomic_cxchg_acq_failrelaxed as atomic_cxchg_acquire_relaxed; - pub use super::atomic_cxchg_acqrel as atomic_cxchg_acqrel_acquire; - pub use super::atomic_cxchg_acqrel_failrelaxed as atomic_cxchg_acqrel_relaxed; - pub use super::atomic_cxchg_failacq as atomic_cxchg_seqcst_acquire; - pub use super::atomic_cxchg_failrelaxed as atomic_cxchg_seqcst_relaxed; - pub use super::atomic_cxchg_rel as atomic_cxchg_release_relaxed; - pub use super::atomic_cxchg_relaxed as atomic_cxchg_relaxed_relaxed; - - pub use super::atomic_cxchgweak as atomic_cxchgweak_seqcst_seqcst; - pub use super::atomic_cxchgweak_acq as atomic_cxchgweak_acquire_acquire; - pub use super::atomic_cxchgweak_acq_failrelaxed as atomic_cxchgweak_acquire_relaxed; - pub use super::atomic_cxchgweak_acqrel as atomic_cxchgweak_acqrel_acquire; - pub use super::atomic_cxchgweak_acqrel_failrelaxed as atomic_cxchgweak_acqrel_relaxed; - pub use super::atomic_cxchgweak_failacq as atomic_cxchgweak_seqcst_acquire; - pub use super::atomic_cxchgweak_failrelaxed as atomic_cxchgweak_seqcst_relaxed; - pub use super::atomic_cxchgweak_rel as atomic_cxchgweak_release_relaxed; - pub use super::atomic_cxchgweak_relaxed as atomic_cxchgweak_relaxed_relaxed; - - pub use super::atomic_load as atomic_load_seqcst; - pub use super::atomic_load_acq as atomic_load_acquire; - pub use super::atomic_load_relaxed; - pub use super::atomic_load_unordered; - - pub use super::atomic_store as atomic_store_seqcst; - pub use super::atomic_store_rel as atomic_store_release; - pub use super::atomic_store_relaxed; - pub use super::atomic_store_unordered; - - pub use super::atomic_xchg as atomic_xchg_seqcst; - pub use super::atomic_xchg_acq as atomic_xchg_acquire; - pub use super::atomic_xchg_acqrel; - pub use super::atomic_xchg_rel as atomic_xchg_release; - pub use super::atomic_xchg_relaxed; - - pub use super::atomic_xadd as atomic_xadd_seqcst; - pub use super::atomic_xadd_acq as atomic_xadd_acquire; - pub use super::atomic_xadd_acqrel; - pub use super::atomic_xadd_rel as atomic_xadd_release; - pub use super::atomic_xadd_relaxed; - - pub use super::atomic_xsub as atomic_xsub_seqcst; - pub use super::atomic_xsub_acq as atomic_xsub_acquire; - pub use super::atomic_xsub_acqrel; - pub use super::atomic_xsub_rel as atomic_xsub_release; - pub use super::atomic_xsub_relaxed; - - pub use super::atomic_and as atomic_and_seqcst; - pub use super::atomic_and_acq as atomic_and_acquire; - pub use super::atomic_and_acqrel; - pub use super::atomic_and_rel as atomic_and_release; - pub use super::atomic_and_relaxed; - - pub use super::atomic_nand as atomic_nand_seqcst; - pub use super::atomic_nand_acq as atomic_nand_acquire; - pub use super::atomic_nand_acqrel; - pub use super::atomic_nand_rel as atomic_nand_release; - pub use super::atomic_nand_relaxed; - - pub use super::atomic_or as atomic_or_seqcst; - pub use super::atomic_or_acq as atomic_or_acquire; - pub use super::atomic_or_acqrel; - pub use super::atomic_or_rel as atomic_or_release; - pub use super::atomic_or_relaxed; - - pub use super::atomic_xor as atomic_xor_seqcst; - pub use super::atomic_xor_acq as atomic_xor_acquire; - pub use super::atomic_xor_acqrel; - pub use super::atomic_xor_rel as atomic_xor_release; - pub use super::atomic_xor_relaxed; - - pub use super::atomic_max as atomic_max_seqcst; - pub use super::atomic_max_acq as atomic_max_acquire; - pub use super::atomic_max_acqrel; - pub use super::atomic_max_rel as atomic_max_release; - pub use super::atomic_max_relaxed; - - pub use super::atomic_min as atomic_min_seqcst; - pub use super::atomic_min_acq as atomic_min_acquire; - pub use super::atomic_min_acqrel; - pub use super::atomic_min_rel as atomic_min_release; - pub use super::atomic_min_relaxed; - - pub use super::atomic_umin as atomic_umin_seqcst; - pub use super::atomic_umin_acq as atomic_umin_acquire; - pub use super::atomic_umin_acqrel; - pub use super::atomic_umin_rel as atomic_umin_release; - pub use super::atomic_umin_relaxed; - - pub use super::atomic_umax as atomic_umax_seqcst; - pub use super::atomic_umax_acq as atomic_umax_acquire; - pub use super::atomic_umax_acqrel; - pub use super::atomic_umax_rel as atomic_umax_release; - pub use super::atomic_umax_relaxed; - - pub use super::atomic_fence as atomic_fence_seqcst; - pub use super::atomic_fence_acq as atomic_fence_acquire; - pub use super::atomic_fence_acqrel; - pub use super::atomic_fence_rel as atomic_fence_release; - - pub use super::atomic_singlethreadfence as atomic_singlethreadfence_seqcst; - pub use super::atomic_singlethreadfence_acq as atomic_singlethreadfence_acquire; - pub use super::atomic_singlethreadfence_acqrel; - pub use super::atomic_singlethreadfence_rel as atomic_singlethreadfence_release; -} - -#[cfg(bootstrap)] -pub use atomics::*; - -#[cfg(not(bootstrap))] extern "rust-intrinsic" { // N.B., these intrinsics take raw pointers because they mutate aliased // memory, which is not valid for either `&` or `&mut`. @@ -945,30 +737,7 @@ extern "rust-intrinsic" { /// [`atomic::compiler_fence`] by passing [`Ordering::AcqRel`] /// as the `order`. pub fn atomic_singlethreadfence_acqrel(); -} - -// These have been renamed. -// -// These are the aliases for the old names. -// To be removed when stdarch and panic_unwind have been updated. -#[cfg(not(bootstrap))] -mod atomics { - pub use super::atomic_cxchg_acqrel_acquire as atomic_cxchg_acqrel; - pub use super::atomic_cxchg_acqrel_relaxed as atomic_cxchg_acqrel_failrelaxed; - pub use super::atomic_cxchg_acquire_acquire as atomic_cxchg_acq; - pub use super::atomic_cxchg_acquire_relaxed as atomic_cxchg_acq_failrelaxed; - pub use super::atomic_cxchg_relaxed_relaxed as atomic_cxchg_relaxed; - pub use super::atomic_cxchg_release_relaxed as atomic_cxchg_rel; - pub use super::atomic_cxchg_seqcst_acquire as atomic_cxchg_failacq; - pub use super::atomic_cxchg_seqcst_relaxed as atomic_cxchg_failrelaxed; - pub use super::atomic_cxchg_seqcst_seqcst as atomic_cxchg; - pub use super::atomic_store_seqcst as atomic_store; -} - -#[cfg(not(bootstrap))] -pub use atomics::*; -extern "rust-intrinsic" { /// The `prefetch` intrinsic is a hint to the code generator to insert a prefetch instruction /// if supported; otherwise, it is a no-op. /// Prefetches have no effect on the behavior of the program but can change its performance @@ -1019,6 +788,7 @@ extern "rust-intrinsic" { /// uninitialized at that point in the control flow. /// /// This intrinsic should not be used outside of the compiler. + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn rustc_peek<T>(_: T) -> T; /// Aborts the execution of the process. @@ -1036,6 +806,7 @@ extern "rust-intrinsic" { /// On Unix, the /// process will probably terminate with a signal like `SIGABRT`, `SIGILL`, `SIGTRAP`, `SIGSEGV` or /// `SIGBUS`. The precise behaviour is not guaranteed and not stable. + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn abort() -> !; /// Informs the optimizer that this point in the code is not reachable, @@ -1074,6 +845,7 @@ extern "rust-intrinsic" { /// /// This intrinsic does not have a stable counterpart. #[rustc_const_unstable(feature = "const_likely", issue = "none")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn likely(b: bool) -> bool; /// Hints to the compiler that branch condition is likely to be false. @@ -1088,6 +860,7 @@ extern "rust-intrinsic" { /// /// This intrinsic does not have a stable counterpart. #[rustc_const_unstable(feature = "const_likely", issue = "none")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn unlikely(b: bool) -> bool; /// Executes a breakpoint trap, for inspection by a debugger. @@ -1107,6 +880,7 @@ extern "rust-intrinsic" { /// /// The stabilized version of this intrinsic is [`core::mem::size_of`]. #[rustc_const_stable(feature = "const_size_of", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn size_of<T>() -> usize; /// The minimum alignment of a type. @@ -1118,6 +892,7 @@ extern "rust-intrinsic" { /// /// The stabilized version of this intrinsic is [`core::mem::align_of`]. #[rustc_const_stable(feature = "const_min_align_of", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn min_align_of<T>() -> usize; /// The preferred alignment of a type. /// @@ -1146,6 +921,7 @@ extern "rust-intrinsic" { /// /// The stabilized version of this intrinsic is [`core::any::type_name`]. #[rustc_const_unstable(feature = "const_type_name", issue = "63084")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn type_name<T: ?Sized>() -> &'static str; /// Gets an identifier which is globally unique to the specified type. This @@ -1159,6 +935,7 @@ extern "rust-intrinsic" { /// /// The stabilized version of this intrinsic is [`core::any::TypeId::of`]. #[rustc_const_unstable(feature = "const_type_id", issue = "77125")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn type_id<T: ?Sized + 'static>() -> u64; /// A guard for unsafe functions that cannot ever be executed if `T` is uninhabited: @@ -1166,6 +943,7 @@ extern "rust-intrinsic" { /// /// This intrinsic does not have a stable counterpart. #[rustc_const_stable(feature = "const_assert_type", since = "1.59.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn assert_inhabited<T>(); /// A guard for unsafe functions that cannot ever be executed if `T` does not permit @@ -1173,6 +951,7 @@ extern "rust-intrinsic" { /// /// This intrinsic does not have a stable counterpart. #[rustc_const_unstable(feature = "const_assert_type2", issue = "none")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn assert_zero_valid<T>(); /// A guard for unsafe functions that cannot ever be executed if `T` has invalid @@ -1180,6 +959,7 @@ extern "rust-intrinsic" { /// /// This intrinsic does not have a stable counterpart. #[rustc_const_unstable(feature = "const_assert_type2", issue = "none")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn assert_uninit_valid<T>(); /// Gets a reference to a static `Location` indicating where it was called. @@ -1191,6 +971,7 @@ extern "rust-intrinsic" { /// /// Consider using [`core::panic::Location::caller`] instead. #[rustc_const_unstable(feature = "const_caller_location", issue = "76156")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn caller_location() -> &'static crate::panic::Location<'static>; /// Moves a value out of scope without running drop glue. @@ -1203,6 +984,7 @@ extern "rust-intrinsic" { /// Therefore, implementations must not require the user to uphold /// any safety invariants. #[rustc_const_unstable(feature = "const_intrinsic_forget", issue = "none")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn forget<T: ?Sized>(_: T); /// Reinterprets the bits of a value of one type as another type. @@ -1212,14 +994,14 @@ extern "rust-intrinsic" { /// `transmute` is semantically equivalent to a bitwise move of one type /// into another. It copies the bits from the source value into the /// destination value, then forgets the original. Note that source and destination - /// are passed by-value, which means if `T` or `U` contain padding, that padding + /// are passed by-value, which means if `Src` or `Dst` contain padding, that padding /// is *not* guaranteed to be preserved by `transmute`. /// /// Both the argument and the result must be [valid](../../nomicon/what-unsafe-does.html) at /// their given type. Violating this condition leads to [undefined behavior][ub]. The compiler /// will generate code *assuming that you, the programmer, ensure that there will never be /// undefined behavior*. It is therefore your responsibility to guarantee that every value - /// passed to `transmute` is valid at both types `T` and `U`. Failing to uphold this condition + /// passed to `transmute` is valid at both types `Src` and `Dst`. Failing to uphold this condition /// may lead to unexpected and unstable compilation results. This makes `transmute` **incredibly /// unsafe**. `transmute` should be the absolute last resort. /// @@ -1230,7 +1012,7 @@ extern "rust-intrinsic" { /// /// Because `transmute` is a by-value operation, alignment of the *transmuted values /// themselves* is not a concern. As with any other function, the compiler already ensures - /// both `T` and `U` are properly aligned. However, when transmuting values that *point + /// both `Src` and `Dst` are properly aligned. However, when transmuting values that *point /// elsewhere* (such as pointers, references, boxes…), the caller has to ensure proper /// alignment of the pointed-to values. /// @@ -1313,7 +1095,7 @@ extern "rust-intrinsic" { /// Note that using `transmute` to turn a pointer to a `usize` is (as noted above) [undefined /// behavior][ub] in `const` contexts. Also outside of consts, this operation might not behave /// as expected -- this is touching on many unspecified aspects of the Rust memory model. - /// Depending on what the code is doing, the following alternatives are preferrable to + /// Depending on what the code is doing, the following alternatives are preferable to /// pointer-to-integer transmutation: /// - If the code just wants to store data of arbitrary type in some buffer and needs to pick a /// type for that buffer, it can use [`MaybeUninit`][mem::MaybeUninit]. @@ -1463,10 +1245,10 @@ extern "rust-intrinsic" { /// } /// ``` #[stable(feature = "rust1", since = "1.0.0")] - #[cfg_attr(not(bootstrap), rustc_allowed_through_unstable_modules)] + #[rustc_allowed_through_unstable_modules] #[rustc_const_stable(feature = "const_transmute", since = "1.56.0")] #[rustc_diagnostic_item = "transmute"] - pub fn transmute<T, U>(e: T) -> U; + pub fn transmute<Src, Dst>(src: Src) -> Dst; /// Returns `true` if the actual type given as `T` requires drop /// glue; returns `false` if the actual type provided for `T` @@ -1482,6 +1264,7 @@ extern "rust-intrinsic" { /// /// The stabilized version of this intrinsic is [`mem::needs_drop`](crate::mem::needs_drop). #[rustc_const_stable(feature = "const_needs_drop", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn needs_drop<T: ?Sized>() -> bool; /// Calculates the offset from a pointer. @@ -1518,6 +1301,17 @@ extern "rust-intrinsic" { #[rustc_const_stable(feature = "const_ptr_offset", since = "1.61.0")] pub fn arith_offset<T>(dst: *const T, offset: isize) -> *const T; + /// Masks out bits of the pointer according to a mask. + /// + /// Note that, unlike most intrinsics, this is safe to call; + /// it does not require an `unsafe` block. + /// Therefore, implementations must not require the user to uphold + /// any safety invariants. + /// + /// Consider using [`pointer::mask`] instead. + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] + pub fn ptr_mask<T>(ptr: *const T, mask: usize) -> *const T; + /// Equivalent to the appropriate `llvm.memcpy.p0i8.0i8.*` intrinsic, with /// a size of `count` * `size_of::<T>()` and an alignment of /// `min_align_of::<T>()` @@ -1707,6 +1501,7 @@ extern "rust-intrinsic" { /// /// The stabilized version of this intrinsic is /// [`f32::min`] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn minnumf32(x: f32, y: f32) -> f32; /// Returns the minimum of two `f64` values. /// @@ -1717,6 +1512,7 @@ extern "rust-intrinsic" { /// /// The stabilized version of this intrinsic is /// [`f64::min`] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn minnumf64(x: f64, y: f64) -> f64; /// Returns the maximum of two `f32` values. /// @@ -1727,6 +1523,7 @@ extern "rust-intrinsic" { /// /// The stabilized version of this intrinsic is /// [`f32::max`] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn maxnumf32(x: f32, y: f32) -> f32; /// Returns the maximum of two `f64` values. /// @@ -1737,6 +1534,7 @@ extern "rust-intrinsic" { /// /// The stabilized version of this intrinsic is /// [`f64::max`] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn maxnumf64(x: f64, y: f64) -> f64; /// Copies the sign from `y` to `x` for `f32` values. @@ -1857,6 +1655,7 @@ extern "rust-intrinsic" { /// primitives via the `count_ones` method. For example, /// [`u32::count_ones`] #[rustc_const_stable(feature = "const_ctpop", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn ctpop<T: Copy>(x: T) -> T; /// Returns the number of leading unset bits (zeroes) in an integer type `T`. @@ -1894,6 +1693,7 @@ extern "rust-intrinsic" { /// assert_eq!(num_leading, 16); /// ``` #[rustc_const_stable(feature = "const_ctlz", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn ctlz<T: Copy>(x: T) -> T; /// Like `ctlz`, but extra-unsafe as it returns `undef` when @@ -1950,6 +1750,7 @@ extern "rust-intrinsic" { /// assert_eq!(num_trailing, 16); /// ``` #[rustc_const_stable(feature = "const_cttz", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn cttz<T: Copy>(x: T) -> T; /// Like `cttz`, but extra-unsafe as it returns `undef` when @@ -1982,6 +1783,7 @@ extern "rust-intrinsic" { /// primitives via the `swap_bytes` method. For example, /// [`u32::swap_bytes`] #[rustc_const_stable(feature = "const_bswap", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn bswap<T: Copy>(x: T) -> T; /// Reverses the bits in an integer type `T`. @@ -1995,6 +1797,7 @@ extern "rust-intrinsic" { /// primitives via the `reverse_bits` method. For example, /// [`u32::reverse_bits`] #[rustc_const_stable(feature = "const_bitreverse", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn bitreverse<T: Copy>(x: T) -> T; /// Performs checked integer addition. @@ -2008,6 +1811,7 @@ extern "rust-intrinsic" { /// primitives via the `overflowing_add` method. For example, /// [`u32::overflowing_add`] #[rustc_const_stable(feature = "const_int_overflow", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn add_with_overflow<T: Copy>(x: T, y: T) -> (T, bool); /// Performs checked integer subtraction @@ -2021,6 +1825,7 @@ extern "rust-intrinsic" { /// primitives via the `overflowing_sub` method. For example, /// [`u32::overflowing_sub`] #[rustc_const_stable(feature = "const_int_overflow", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn sub_with_overflow<T: Copy>(x: T, y: T) -> (T, bool); /// Performs checked integer multiplication @@ -2034,6 +1839,7 @@ extern "rust-intrinsic" { /// primitives via the `overflowing_mul` method. For example, /// [`u32::overflowing_mul`] #[rustc_const_stable(feature = "const_int_overflow", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn mul_with_overflow<T: Copy>(x: T, y: T) -> (T, bool); /// Performs an exact division, resulting in undefined behavior where @@ -2108,6 +1914,7 @@ extern "rust-intrinsic" { /// primitives via the `rotate_left` method. For example, /// [`u32::rotate_left`] #[rustc_const_stable(feature = "const_int_rotate", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn rotate_left<T: Copy>(x: T, y: T) -> T; /// Performs rotate right. @@ -2121,6 +1928,7 @@ extern "rust-intrinsic" { /// primitives via the `rotate_right` method. For example, /// [`u32::rotate_right`] #[rustc_const_stable(feature = "const_int_rotate", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn rotate_right<T: Copy>(x: T, y: T) -> T; /// Returns (a + b) mod 2<sup>N</sup>, where N is the width of T in bits. @@ -2134,6 +1942,7 @@ extern "rust-intrinsic" { /// primitives via the `wrapping_add` method. For example, /// [`u32::wrapping_add`] #[rustc_const_stable(feature = "const_int_wrapping", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn wrapping_add<T: Copy>(a: T, b: T) -> T; /// Returns (a - b) mod 2<sup>N</sup>, where N is the width of T in bits. /// @@ -2146,6 +1955,7 @@ extern "rust-intrinsic" { /// primitives via the `wrapping_sub` method. For example, /// [`u32::wrapping_sub`] #[rustc_const_stable(feature = "const_int_wrapping", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn wrapping_sub<T: Copy>(a: T, b: T) -> T; /// Returns (a * b) mod 2<sup>N</sup>, where N is the width of T in bits. /// @@ -2158,6 +1968,7 @@ extern "rust-intrinsic" { /// primitives via the `wrapping_mul` method. For example, /// [`u32::wrapping_mul`] #[rustc_const_stable(feature = "const_int_wrapping", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn wrapping_mul<T: Copy>(a: T, b: T) -> T; /// Computes `a + b`, saturating at numeric bounds. @@ -2171,6 +1982,7 @@ extern "rust-intrinsic" { /// primitives via the `saturating_add` method. For example, /// [`u32::saturating_add`] #[rustc_const_stable(feature = "const_int_saturating", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn saturating_add<T: Copy>(a: T, b: T) -> T; /// Computes `a - b`, saturating at numeric bounds. /// @@ -2183,6 +1995,7 @@ extern "rust-intrinsic" { /// primitives via the `saturating_sub` method. For example, /// [`u32::saturating_sub`] #[rustc_const_stable(feature = "const_int_saturating", since = "1.40.0")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn saturating_sub<T: Copy>(a: T, b: T) -> T; /// Returns the value of the discriminant for the variant in 'v'; @@ -2195,6 +2008,7 @@ extern "rust-intrinsic" { /// /// The stabilized version of this intrinsic is [`core::mem::discriminant`]. #[rustc_const_unstable(feature = "const_discriminant", issue = "69821")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn discriminant_value<T>(v: &T) -> <T as DiscriminantKind>::Discriminant; /// Returns the number of variants of the type `T` cast to a `usize`; @@ -2207,6 +2021,7 @@ extern "rust-intrinsic" { /// /// The to-be-stabilized version of this intrinsic is [`mem::variant_count`]. #[rustc_const_unstable(feature = "variant_count", issue = "73662")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn variant_count<T>() -> usize; /// Rust's "try catch" construct which invokes the function pointer `try_fn` @@ -2223,30 +2038,25 @@ extern "rust-intrinsic" { pub fn nontemporal_store<T>(ptr: *mut T, val: T); /// See documentation of `<*const T>::offset_from` for details. - #[rustc_const_unstable(feature = "const_ptr_offset_from", issue = "92980")] + #[rustc_const_stable(feature = "const_ptr_offset_from", since = "1.65.0")] pub fn ptr_offset_from<T>(ptr: *const T, base: *const T) -> isize; /// See documentation of `<*const T>::sub_ptr` for details. - #[rustc_const_unstable(feature = "const_ptr_offset_from", issue = "92980")] + #[rustc_const_unstable(feature = "const_ptr_sub_ptr", issue = "95892")] pub fn ptr_offset_from_unsigned<T>(ptr: *const T, base: *const T) -> usize; /// See documentation of `<*const T>::guaranteed_eq` for details. + /// Returns `2` if the result is unknown. + /// Returns `1` if the pointers are guaranteed equal + /// Returns `0` if the pointers are guaranteed inequal /// /// Note that, unlike most intrinsics, this is safe to call; /// it does not require an `unsafe` block. /// Therefore, implementations must not require the user to uphold /// any safety invariants. #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] - pub fn ptr_guaranteed_eq<T>(ptr: *const T, other: *const T) -> bool; - - /// See documentation of `<*const T>::guaranteed_ne` for details. - /// - /// Note that, unlike most intrinsics, this is safe to call; - /// it does not require an `unsafe` block. - /// Therefore, implementations must not require the user to uphold - /// any safety invariants. - #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] - pub fn ptr_guaranteed_ne<T>(ptr: *const T, other: *const T) -> bool; + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] + pub fn ptr_guaranteed_cmp<T>(ptr: *const T, other: *const T) -> u8; /// Allocates a block of memory at compile time. /// At runtime, just returns a null pointer. @@ -2282,7 +2092,8 @@ extern "rust-intrinsic" { /// /// # Safety /// - /// It's UB to call this if any of the *bytes* in `*a` or `*b` are uninitialized. + /// It's UB to call this if any of the *bytes* in `*a` or `*b` are uninitialized or carry a + /// pointer value. /// Note that this is a stricter criterion than just the *values* being /// fully-initialized: if `T` has padding, it's UB to call this intrinsic. /// @@ -2295,17 +2106,74 @@ extern "rust-intrinsic" { /// /// [`std::hint::black_box`]: crate::hint::black_box #[rustc_const_unstable(feature = "const_black_box", issue = "none")] + #[cfg_attr(not(bootstrap), rustc_safe_intrinsic)] pub fn black_box<T>(dummy: T) -> T; /// `ptr` must point to a vtable. /// The intrinsic will return the size stored in that vtable. - #[cfg(not(bootstrap))] pub fn vtable_size(ptr: *const ()) -> usize; /// `ptr` must point to a vtable. /// The intrinsic will return the alignment stored in that vtable. - #[cfg(not(bootstrap))] pub fn vtable_align(ptr: *const ()) -> usize; + + /// Selects which function to call depending on the context. + /// + /// If this function is evaluated at compile-time, then a call to this + /// intrinsic will be replaced with a call to `called_in_const`. It gets + /// replaced with a call to `called_at_rt` otherwise. + /// + /// # Type Requirements + /// + /// The two functions must be both function items. They cannot be function + /// pointers or closures. The first function must be a `const fn`. + /// + /// `arg` will be the tupled arguments that will be passed to either one of + /// the two functions, therefore, both functions must accept the same type of + /// arguments. Both functions must return RET. + /// + /// # Safety + /// + /// The two functions must behave observably equivalent. Safe code in other + /// crates may assume that calling a `const fn` at compile-time and at run-time + /// produces the same result. A function that produces a different result when + /// evaluated at run-time, or has any other observable side-effects, is + /// *unsound*. + /// + /// Here is an example of how this could cause a problem: + /// ```no_run + /// #![feature(const_eval_select)] + /// #![feature(core_intrinsics)] + /// use std::hint::unreachable_unchecked; + /// use std::intrinsics::const_eval_select; + /// + /// // Crate A + /// pub const fn inconsistent() -> i32 { + /// fn runtime() -> i32 { 1 } + /// const fn compiletime() -> i32 { 2 } + /// + /// unsafe { + // // ⚠ This code violates the required equivalence of `compiletime` + /// // and `runtime`. + /// const_eval_select((), compiletime, runtime) + /// } + /// } + /// + /// // Crate B + /// const X: i32 = inconsistent(); + /// let x = inconsistent(); + /// if x != X { unsafe { unreachable_unchecked(); }} + /// ``` + /// + /// This code causes Undefined Behavior when being run, since the + /// `unreachable_unchecked` is actually being reached. The bug is in *crate A*, + /// which violates the principle that a `const fn` must behave the same at + /// compile-time and at run-time. The unsafe code in crate B is fine. + #[rustc_const_unstable(feature = "const_eval_select", issue = "none")] + pub fn const_eval_select<ARG, F, G, RET>(arg: ARG, called_in_const: F, called_at_rt: G) -> RET + where + G: FnOnce<ARG, Output = RET>, + F: FnOnce<ARG, Output = RET>; } // Some functions are defined here because they accidentally got made @@ -2316,6 +2184,11 @@ extern "rust-intrinsic" { /// Check that the preconditions of an unsafe function are followed, if debug_assertions are on, /// and only at runtime. /// +/// This macro should be called as `assert_unsafe_precondition!([Generics](name: Type) => Expression)` +/// where the names specified will be moved into the macro as captured variables, and defines an item +/// to call `const_eval_select` on. The tokens inside the square brackets are used to denote generics +/// for the function declaractions and can be omitted if there is no generics. +/// /// # Safety /// /// Invoking this macro is only sound if the following code is already UB when the passed @@ -2330,18 +2203,23 @@ extern "rust-intrinsic" { /// the occasional mistake, and this check should help them figure things out. #[allow_internal_unstable(const_eval_select)] // permit this to be called in stably-const fn macro_rules! assert_unsafe_precondition { - ($e:expr) => { + ($name:expr, $([$($tt:tt)*])?($($i:ident:$ty:ty),*$(,)?) => $e:expr) => { if cfg!(debug_assertions) { - // Use a closure so that we can capture arbitrary expressions from the invocation - let runtime = || { + // allow non_snake_case to allow capturing const generics + #[allow(non_snake_case)] + #[inline(always)] + fn runtime$(<$($tt)*>)?($($i:$ty),*) { if !$e { - // abort instead of panicking to reduce impact on code size - ::core::intrinsics::abort(); + // don't unwind to reduce impact on code size + ::core::panicking::panic_str_nounwind( + concat!("unsafe precondition(s) violated: ", $name) + ); } - }; - const fn comptime() {} + } + #[allow(non_snake_case)] + const fn comptime$(<$($tt)*>)?($(_:$ty),*) {} - ::core::intrinsics::const_eval_select((), comptime, runtime); + ::core::intrinsics::const_eval_select(($($i,)*), comptime, runtime); } }; } @@ -2350,7 +2228,17 @@ pub(crate) use assert_unsafe_precondition; /// Checks whether `ptr` is properly aligned with respect to /// `align_of::<T>()`. pub(crate) fn is_aligned_and_not_null<T>(ptr: *const T) -> bool { - !ptr.is_null() && ptr.addr() % mem::align_of::<T>() == 0 + !ptr.is_null() && ptr.is_aligned() +} + +/// Checks whether an allocation of `len` instances of `T` exceeds +/// the maximum allowed allocation size. +pub(crate) fn is_valid_allocation_size<T>(len: usize) -> bool { + let max_len = const { + let size = crate::mem::size_of::<T>(); + if size == 0 { usize::MAX } else { isize::MAX as usize / size } + }; + len <= max_len } /// Checks whether the regions of memory starting at `src` and `dst` of size @@ -2420,9 +2308,9 @@ pub(crate) fn is_nonoverlapping<T>(src: *const T, dst: *const T, count: usize) - /// dst.reserve(src_len); /// /// unsafe { -/// // The call to offset is always safe because `Vec` will never +/// // The call to add is always safe because `Vec` will never /// // allocate more than `isize::MAX` bytes. -/// let dst_ptr = dst.as_mut_ptr().offset(dst_len as isize); +/// let dst_ptr = dst.as_mut_ptr().add(dst_len); /// let src_ptr = src.as_ptr(); /// /// // Truncate `src` without dropping its contents. We do this first, @@ -2451,7 +2339,7 @@ pub(crate) fn is_nonoverlapping<T>(src: *const T, dst: *const T, count: usize) - /// [`Vec::append`]: ../../std/vec/struct.Vec.html#method.append #[doc(alias = "memcpy")] #[stable(feature = "rust1", since = "1.0.0")] -#[cfg_attr(not(bootstrap), rustc_allowed_through_unstable_modules)] +#[rustc_allowed_through_unstable_modules] #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.63.0")] #[inline] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces @@ -2465,6 +2353,9 @@ pub const unsafe fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: us // upheld by the caller. unsafe { assert_unsafe_precondition!( + "ptr::copy_nonoverlapping requires that both pointer arguments are aligned and non-null \ + and the specified memory ranges do not overlap", + [T](src: *const T, dst: *mut T, count: usize) => is_aligned_and_not_null(src) && is_aligned_and_not_null(dst) && is_nonoverlapping(src, dst, count) @@ -2538,7 +2429,7 @@ pub const unsafe fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: us /// ``` #[doc(alias = "memmove")] #[stable(feature = "rust1", since = "1.0.0")] -#[cfg_attr(not(bootstrap), rustc_allowed_through_unstable_modules)] +#[rustc_allowed_through_unstable_modules] #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.63.0")] #[inline] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces @@ -2550,7 +2441,11 @@ pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) { // SAFETY: the safety contract for `copy` must be upheld by the caller. unsafe { - assert_unsafe_precondition!(is_aligned_and_not_null(src) && is_aligned_and_not_null(dst)); + assert_unsafe_precondition!( + "ptr::copy requires that both pointer arguments are aligned aligned and non-null", + [T](src: *const T, dst: *mut T) => + is_aligned_and_not_null(src) && is_aligned_and_not_null(dst) + ); copy(src, dst, count) } } @@ -2606,7 +2501,7 @@ pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) { /// ``` #[doc(alias = "memset")] #[stable(feature = "rust1", since = "1.0.0")] -#[cfg_attr(not(bootstrap), rustc_allowed_through_unstable_modules)] +#[rustc_allowed_through_unstable_modules] #[rustc_const_unstable(feature = "const_ptr_write", issue = "86302")] #[inline] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces @@ -2618,99 +2513,10 @@ pub const unsafe fn write_bytes<T>(dst: *mut T, val: u8, count: usize) { // SAFETY: the safety contract for `write_bytes` must be upheld by the caller. unsafe { - assert_unsafe_precondition!(is_aligned_and_not_null(dst)); + assert_unsafe_precondition!( + "ptr::write_bytes requires that the destination pointer is aligned and non-null", + [T](dst: *mut T) => is_aligned_and_not_null(dst) + ); write_bytes(dst, val, count) } } - -/// Selects which function to call depending on the context. -/// -/// If this function is evaluated at compile-time, then a call to this -/// intrinsic will be replaced with a call to `called_in_const`. It gets -/// replaced with a call to `called_at_rt` otherwise. -/// -/// # Type Requirements -/// -/// The two functions must be both function items. They cannot be function -/// pointers or closures. -/// -/// `arg` will be the arguments that will be passed to either one of the -/// two functions, therefore, both functions must accept the same type of -/// arguments. Both functions must return RET. -/// -/// # Safety -/// -/// The two functions must behave observably equivalent. Safe code in other -/// crates may assume that calling a `const fn` at compile-time and at run-time -/// produces the same result. A function that produces a different result when -/// evaluated at run-time, or has any other observable side-effects, is -/// *unsound*. -/// -/// Here is an example of how this could cause a problem: -/// ```no_run -/// #![feature(const_eval_select)] -/// #![feature(core_intrinsics)] -/// use std::hint::unreachable_unchecked; -/// use std::intrinsics::const_eval_select; -/// -/// // Crate A -/// pub const fn inconsistent() -> i32 { -/// fn runtime() -> i32 { 1 } -/// const fn compiletime() -> i32 { 2 } -/// -/// unsafe { -// // ⚠ This code violates the required equivalence of `compiletime` -/// // and `runtime`. -/// const_eval_select((), compiletime, runtime) -/// } -/// } -/// -/// // Crate B -/// const X: i32 = inconsistent(); -/// let x = inconsistent(); -/// if x != X { unsafe { unreachable_unchecked(); }} -/// ``` -/// -/// This code causes Undefined Behavior when being run, since the -/// `unreachable_unchecked` is actually being reached. The bug is in *crate A*, -/// which violates the principle that a `const fn` must behave the same at -/// compile-time and at run-time. The unsafe code in crate B is fine. -#[unstable( - feature = "const_eval_select", - issue = "none", - reason = "const_eval_select will never be stable" -)] -#[rustc_const_unstable(feature = "const_eval_select", issue = "none")] -#[lang = "const_eval_select"] -#[rustc_do_not_const_check] -#[inline] -pub const unsafe fn const_eval_select<ARG, F, G, RET>( - arg: ARG, - _called_in_const: F, - called_at_rt: G, -) -> RET -where - F: ~const FnOnce<ARG, Output = RET>, - G: FnOnce<ARG, Output = RET> + ~const Destruct, -{ - called_at_rt.call_once(arg) -} - -#[unstable( - feature = "const_eval_select", - issue = "none", - reason = "const_eval_select will never be stable" -)] -#[rustc_const_unstable(feature = "const_eval_select", issue = "none")] -#[lang = "const_eval_select_ct"] -pub const unsafe fn const_eval_select_ct<ARG, F, G, RET>( - arg: ARG, - called_in_const: F, - _called_at_rt: G, -) -> RET -where - F: ~const FnOnce<ARG, Output = RET>, - G: FnOnce<ARG, Output = RET> + ~const Destruct, -{ - called_in_const.call_once(arg) -} diff --git a/library/core/src/iter/adapters/array_chunks.rs b/library/core/src/iter/adapters/array_chunks.rs new file mode 100644 index 000000000..d4fb88610 --- /dev/null +++ b/library/core/src/iter/adapters/array_chunks.rs @@ -0,0 +1,170 @@ +use crate::array; +use crate::iter::{ByRefSized, FusedIterator, Iterator}; +use crate::ops::{ControlFlow, Try}; + +/// An iterator over `N` elements of the iterator at a time. +/// +/// The chunks do not overlap. If `N` does not divide the length of the +/// iterator, then the last up to `N-1` elements will be omitted. +/// +/// This `struct` is created by the [`array_chunks`][Iterator::array_chunks] +/// method on [`Iterator`]. See its documentation for more. +#[derive(Debug, Clone)] +#[must_use = "iterators are lazy and do nothing unless consumed"] +#[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "100450")] +pub struct ArrayChunks<I: Iterator, const N: usize> { + iter: I, + remainder: Option<array::IntoIter<I::Item, N>>, +} + +impl<I, const N: usize> ArrayChunks<I, N> +where + I: Iterator, +{ + #[track_caller] + pub(in crate::iter) fn new(iter: I) -> Self { + assert!(N != 0, "chunk size must be non-zero"); + Self { iter, remainder: None } + } + + /// Returns an iterator over the remaining elements of the original iterator + /// that are not going to be returned by this iterator. The returned + /// iterator will yield at most `N-1` elements. + #[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "100450")] + #[inline] + pub fn into_remainder(self) -> Option<array::IntoIter<I::Item, N>> { + self.remainder + } +} + +#[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "100450")] +impl<I, const N: usize> Iterator for ArrayChunks<I, N> +where + I: Iterator, +{ + type Item = [I::Item; N]; + + #[inline] + fn next(&mut self) -> Option<Self::Item> { + self.try_for_each(ControlFlow::Break).break_value() + } + + #[inline] + fn size_hint(&self) -> (usize, Option<usize>) { + let (lower, upper) = self.iter.size_hint(); + + (lower / N, upper.map(|n| n / N)) + } + + #[inline] + fn count(self) -> usize { + self.iter.count() / N + } + + fn try_fold<B, F, R>(&mut self, init: B, mut f: F) -> R + where + Self: Sized, + F: FnMut(B, Self::Item) -> R, + R: Try<Output = B>, + { + let mut acc = init; + loop { + match self.iter.next_chunk() { + Ok(chunk) => acc = f(acc, chunk)?, + Err(remainder) => { + // Make sure to not override `self.remainder` with an empty array + // when `next` is called after `ArrayChunks` exhaustion. + self.remainder.get_or_insert(remainder); + + break try { acc }; + } + } + } + } + + impl_fold_via_try_fold! { fold -> try_fold } +} + +#[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "100450")] +impl<I, const N: usize> DoubleEndedIterator for ArrayChunks<I, N> +where + I: DoubleEndedIterator + ExactSizeIterator, +{ + #[inline] + fn next_back(&mut self) -> Option<Self::Item> { + self.try_rfold((), |(), x| ControlFlow::Break(x)).break_value() + } + + fn try_rfold<B, F, R>(&mut self, init: B, mut f: F) -> R + where + Self: Sized, + F: FnMut(B, Self::Item) -> R, + R: Try<Output = B>, + { + // We are iterating from the back we need to first handle the remainder. + self.next_back_remainder(); + + let mut acc = init; + let mut iter = ByRefSized(&mut self.iter).rev(); + + // NB remainder is handled by `next_back_remainder`, so + // `next_chunk` can't return `Err` with non-empty remainder + // (assuming correct `I as ExactSizeIterator` impl). + while let Ok(mut chunk) = iter.next_chunk() { + // FIXME: do not do double reverse + // (we could instead add `next_chunk_back` for example) + chunk.reverse(); + acc = f(acc, chunk)? + } + + try { acc } + } + + impl_fold_via_try_fold! { rfold -> try_rfold } +} + +impl<I, const N: usize> ArrayChunks<I, N> +where + I: DoubleEndedIterator + ExactSizeIterator, +{ + /// Updates `self.remainder` such that `self.iter.len` is divisible by `N`. + fn next_back_remainder(&mut self) { + // Make sure to not override `self.remainder` with an empty array + // when `next_back` is called after `ArrayChunks` exhaustion. + if self.remainder.is_some() { + return; + } + + // We use the `ExactSizeIterator` implementation of the underlying + // iterator to know how many remaining elements there are. + let rem = self.iter.len() % N; + + // Take the last `rem` elements out of `self.iter`. + let mut remainder = + // SAFETY: `unwrap_err` always succeeds because x % N < N for all x. + unsafe { self.iter.by_ref().rev().take(rem).next_chunk().unwrap_err_unchecked() }; + + // We used `.rev()` above, so we need to re-reverse the reminder + remainder.as_mut_slice().reverse(); + self.remainder = Some(remainder); + } +} + +#[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "100450")] +impl<I, const N: usize> FusedIterator for ArrayChunks<I, N> where I: FusedIterator {} + +#[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "100450")] +impl<I, const N: usize> ExactSizeIterator for ArrayChunks<I, N> +where + I: ExactSizeIterator, +{ + #[inline] + fn len(&self) -> usize { + self.iter.len() / N + } + + #[inline] + fn is_empty(&self) -> bool { + self.iter.len() < N + } +} diff --git a/library/core/src/iter/adapters/by_ref_sized.rs b/library/core/src/iter/adapters/by_ref_sized.rs index cc1e8e8a2..1945e402f 100644 --- a/library/core/src/iter/adapters/by_ref_sized.rs +++ b/library/core/src/iter/adapters/by_ref_sized.rs @@ -1,4 +1,7 @@ -use crate::ops::Try; +use crate::{ + const_closure::ConstFnMutClosure, + ops::{NeverShortCircuit, Try}, +}; /// Like `Iterator::by_ref`, but requiring `Sized` so it can forward generics. /// @@ -8,36 +11,41 @@ use crate::ops::Try; #[derive(Debug)] pub struct ByRefSized<'a, I>(pub &'a mut I); +// The following implementations use UFCS-style, rather than trusting autoderef, +// to avoid accidentally calling the `&mut Iterator` implementations. + #[unstable(feature = "std_internals", issue = "none")] impl<I: Iterator> Iterator for ByRefSized<'_, I> { type Item = I::Item; #[inline] fn next(&mut self) -> Option<Self::Item> { - self.0.next() + I::next(self.0) } #[inline] fn size_hint(&self) -> (usize, Option<usize>) { - self.0.size_hint() + I::size_hint(self.0) } #[inline] fn advance_by(&mut self, n: usize) -> Result<(), usize> { - self.0.advance_by(n) + I::advance_by(self.0, n) } #[inline] fn nth(&mut self, n: usize) -> Option<Self::Item> { - self.0.nth(n) + I::nth(self.0, n) } #[inline] - fn fold<B, F>(self, init: B, f: F) -> B + fn fold<B, F>(self, init: B, mut f: F) -> B where F: FnMut(B, Self::Item) -> B, { - self.0.fold(init, f) + // `fold` needs ownership, so this can't forward directly. + I::try_fold(self.0, init, ConstFnMutClosure::new(&mut f, NeverShortCircuit::wrap_mut_2_imp)) + .0 } #[inline] @@ -46,7 +54,7 @@ impl<I: Iterator> Iterator for ByRefSized<'_, I> { F: FnMut(B, Self::Item) -> R, R: Try<Output = B>, { - self.0.try_fold(init, f) + I::try_fold(self.0, init, f) } } @@ -54,25 +62,31 @@ impl<I: Iterator> Iterator for ByRefSized<'_, I> { impl<I: DoubleEndedIterator> DoubleEndedIterator for ByRefSized<'_, I> { #[inline] fn next_back(&mut self) -> Option<Self::Item> { - self.0.next_back() + I::next_back(self.0) } #[inline] fn advance_back_by(&mut self, n: usize) -> Result<(), usize> { - self.0.advance_back_by(n) + I::advance_back_by(self.0, n) } #[inline] fn nth_back(&mut self, n: usize) -> Option<Self::Item> { - self.0.nth_back(n) + I::nth_back(self.0, n) } #[inline] - fn rfold<B, F>(self, init: B, f: F) -> B + fn rfold<B, F>(self, init: B, mut f: F) -> B where F: FnMut(B, Self::Item) -> B, { - self.0.rfold(init, f) + // `rfold` needs ownership, so this can't forward directly. + I::try_rfold( + self.0, + init, + ConstFnMutClosure::new(&mut f, NeverShortCircuit::wrap_mut_2_imp), + ) + .0 } #[inline] @@ -81,6 +95,6 @@ impl<I: DoubleEndedIterator> DoubleEndedIterator for ByRefSized<'_, I> { F: FnMut(B, Self::Item) -> R, R: Try<Output = B>, { - self.0.try_rfold(init, f) + I::try_rfold(self.0, init, f) } } diff --git a/library/core/src/iter/adapters/copied.rs b/library/core/src/iter/adapters/copied.rs index f9bfd77d7..62d3afb81 100644 --- a/library/core/src/iter/adapters/copied.rs +++ b/library/core/src/iter/adapters/copied.rs @@ -2,7 +2,10 @@ use crate::iter::adapters::{ zip::try_get_unchecked, TrustedRandomAccess, TrustedRandomAccessNoCoerce, }; use crate::iter::{FusedIterator, TrustedLen}; +use crate::mem::MaybeUninit; +use crate::mem::SizedTypeProperties; use crate::ops::Try; +use crate::{array, ptr}; /// An iterator that copies the elements of an underlying iterator. /// @@ -44,6 +47,15 @@ where self.it.next().copied() } + fn next_chunk<const N: usize>( + &mut self, + ) -> Result<[Self::Item; N], array::IntoIter<Self::Item, N>> + where + Self: Sized, + { + <I as SpecNextChunk<'_, N, T>>::spec_next_chunk(&mut self.it) + } + fn size_hint(&self) -> (usize, Option<usize>) { self.it.size_hint() } @@ -166,3 +178,65 @@ where T: Copy, { } + +trait SpecNextChunk<'a, const N: usize, T: 'a>: Iterator<Item = &'a T> +where + T: Copy, +{ + fn spec_next_chunk(&mut self) -> Result<[T; N], array::IntoIter<T, N>>; +} + +impl<'a, const N: usize, I, T: 'a> SpecNextChunk<'a, N, T> for I +where + I: Iterator<Item = &'a T>, + T: Copy, +{ + default fn spec_next_chunk(&mut self) -> Result<[T; N], array::IntoIter<T, N>> { + array::iter_next_chunk(&mut self.map(|e| *e)) + } +} + +impl<'a, const N: usize, T: 'a> SpecNextChunk<'a, N, T> for crate::slice::Iter<'a, T> +where + T: Copy, +{ + fn spec_next_chunk(&mut self) -> Result<[T; N], array::IntoIter<T, N>> { + let mut raw_array = MaybeUninit::uninit_array(); + + let len = self.len(); + + if T::IS_ZST { + if len < N { + let _ = self.advance_by(len); + // SAFETY: ZSTs can be conjured ex nihilo; only the amount has to be correct + return Err(unsafe { array::IntoIter::new_unchecked(raw_array, 0..len) }); + } + + let _ = self.advance_by(N); + // SAFETY: ditto + return Ok(unsafe { MaybeUninit::array_assume_init(raw_array) }); + } + + if len < N { + // SAFETY: `len` indicates that this many elements are available and we just checked that + // it fits into the array. + unsafe { + ptr::copy_nonoverlapping( + self.as_ref().as_ptr(), + raw_array.as_mut_ptr() as *mut T, + len, + ); + let _ = self.advance_by(len); + return Err(array::IntoIter::new_unchecked(raw_array, 0..len)); + } + } + + // SAFETY: `len` is larger than the array size. Copy a fixed amount here to fully initialize + // the array. + unsafe { + ptr::copy_nonoverlapping(self.as_ref().as_ptr(), raw_array.as_mut_ptr() as *mut T, N); + let _ = self.advance_by(N); + Ok(MaybeUninit::array_assume_init(raw_array)) + } + } +} diff --git a/library/core/src/iter/adapters/flatten.rs b/library/core/src/iter/adapters/flatten.rs index 15a120e35..307016c26 100644 --- a/library/core/src/iter/adapters/flatten.rs +++ b/library/core/src/iter/adapters/flatten.rs @@ -1,6 +1,6 @@ use crate::fmt; use crate::iter::{DoubleEndedIterator, Fuse, FusedIterator, Iterator, Map, TrustedLen}; -use crate::ops::Try; +use crate::ops::{ControlFlow, Try}; /// An iterator that maps each element to an iterator, and yields the elements /// of the produced iterators. @@ -73,6 +73,21 @@ where { self.inner.fold(init, fold) } + + #[inline] + fn advance_by(&mut self, n: usize) -> Result<(), usize> { + self.inner.advance_by(n) + } + + #[inline] + fn count(self) -> usize { + self.inner.count() + } + + #[inline] + fn last(self) -> Option<Self::Item> { + self.inner.last() + } } #[stable(feature = "rust1", since = "1.0.0")] @@ -103,6 +118,11 @@ where { self.inner.rfold(init, fold) } + + #[inline] + fn advance_back_by(&mut self, n: usize) -> Result<(), usize> { + self.inner.advance_back_by(n) + } } #[stable(feature = "fused", since = "1.26.0")] @@ -214,6 +234,21 @@ where { self.inner.fold(init, fold) } + + #[inline] + fn advance_by(&mut self, n: usize) -> Result<(), usize> { + self.inner.advance_by(n) + } + + #[inline] + fn count(self) -> usize { + self.inner.count() + } + + #[inline] + fn last(self) -> Option<Self::Item> { + self.inner.last() + } } #[stable(feature = "iterator_flatten", since = "1.29.0")] @@ -244,6 +279,11 @@ where { self.inner.rfold(init, fold) } + + #[inline] + fn advance_back_by(&mut self, n: usize) -> Result<(), usize> { + self.inner.advance_back_by(n) + } } #[stable(feature = "iterator_flatten", since = "1.29.0")] @@ -280,6 +320,144 @@ where } } +impl<I, U> FlattenCompat<I, U> +where + I: Iterator<Item: IntoIterator<IntoIter = U>>, +{ + /// Folds the inner iterators into an accumulator by applying an operation. + /// + /// Folds over the inner iterators, not over their elements. Is used by the `fold`, `count`, + /// and `last` methods. + #[inline] + fn iter_fold<Acc, Fold>(self, mut acc: Acc, mut fold: Fold) -> Acc + where + Fold: FnMut(Acc, U) -> Acc, + { + #[inline] + fn flatten<T: IntoIterator, Acc>( + fold: &mut impl FnMut(Acc, T::IntoIter) -> Acc, + ) -> impl FnMut(Acc, T) -> Acc + '_ { + move |acc, iter| fold(acc, iter.into_iter()) + } + + if let Some(iter) = self.frontiter { + acc = fold(acc, iter); + } + + acc = self.iter.fold(acc, flatten(&mut fold)); + + if let Some(iter) = self.backiter { + acc = fold(acc, iter); + } + + acc + } + + /// Folds over the inner iterators as long as the given function returns successfully, + /// always storing the most recent inner iterator in `self.frontiter`. + /// + /// Folds over the inner iterators, not over their elements. Is used by the `try_fold` and + /// `advance_by` methods. + #[inline] + fn iter_try_fold<Acc, Fold, R>(&mut self, mut acc: Acc, mut fold: Fold) -> R + where + Fold: FnMut(Acc, &mut U) -> R, + R: Try<Output = Acc>, + { + #[inline] + fn flatten<'a, T: IntoIterator, Acc, R: Try<Output = Acc>>( + frontiter: &'a mut Option<T::IntoIter>, + fold: &'a mut impl FnMut(Acc, &mut T::IntoIter) -> R, + ) -> impl FnMut(Acc, T) -> R + 'a { + move |acc, iter| fold(acc, frontiter.insert(iter.into_iter())) + } + + if let Some(iter) = &mut self.frontiter { + acc = fold(acc, iter)?; + } + self.frontiter = None; + + acc = self.iter.try_fold(acc, flatten(&mut self.frontiter, &mut fold))?; + self.frontiter = None; + + if let Some(iter) = &mut self.backiter { + acc = fold(acc, iter)?; + } + self.backiter = None; + + try { acc } + } +} + +impl<I, U> FlattenCompat<I, U> +where + I: DoubleEndedIterator<Item: IntoIterator<IntoIter = U>>, +{ + /// Folds the inner iterators into an accumulator by applying an operation, starting form the + /// back. + /// + /// Folds over the inner iterators, not over their elements. Is used by the `rfold` method. + #[inline] + fn iter_rfold<Acc, Fold>(self, mut acc: Acc, mut fold: Fold) -> Acc + where + Fold: FnMut(Acc, U) -> Acc, + { + #[inline] + fn flatten<T: IntoIterator, Acc>( + fold: &mut impl FnMut(Acc, T::IntoIter) -> Acc, + ) -> impl FnMut(Acc, T) -> Acc + '_ { + move |acc, iter| fold(acc, iter.into_iter()) + } + + if let Some(iter) = self.backiter { + acc = fold(acc, iter); + } + + acc = self.iter.rfold(acc, flatten(&mut fold)); + + if let Some(iter) = self.frontiter { + acc = fold(acc, iter); + } + + acc + } + + /// Folds over the inner iterators in reverse order as long as the given function returns + /// successfully, always storing the most recent inner iterator in `self.backiter`. + /// + /// Folds over the inner iterators, not over their elements. Is used by the `try_rfold` and + /// `advance_back_by` methods. + #[inline] + fn iter_try_rfold<Acc, Fold, R>(&mut self, mut acc: Acc, mut fold: Fold) -> R + where + Fold: FnMut(Acc, &mut U) -> R, + R: Try<Output = Acc>, + { + #[inline] + fn flatten<'a, T: IntoIterator, Acc, R: Try>( + backiter: &'a mut Option<T::IntoIter>, + fold: &'a mut impl FnMut(Acc, &mut T::IntoIter) -> R, + ) -> impl FnMut(Acc, T) -> R + 'a { + move |acc, iter| fold(acc, backiter.insert(iter.into_iter())) + } + + if let Some(iter) = &mut self.backiter { + acc = fold(acc, iter)?; + } + self.backiter = None; + + acc = self.iter.try_rfold(acc, flatten(&mut self.backiter, &mut fold))?; + self.backiter = None; + + if let Some(iter) = &mut self.frontiter { + acc = fold(acc, iter)?; + } + self.frontiter = None; + + try { acc } + } +} + impl<I, U> Iterator for FlattenCompat<I, U> where I: Iterator<Item: IntoIterator<IntoIter = U, Item = U::Item>>, @@ -323,99 +501,74 @@ where } #[inline] - fn try_fold<Acc, Fold, R>(&mut self, mut init: Acc, mut fold: Fold) -> R + fn try_fold<Acc, Fold, R>(&mut self, init: Acc, fold: Fold) -> R where Self: Sized, Fold: FnMut(Acc, Self::Item) -> R, R: Try<Output = Acc>, { #[inline] - fn flatten<'a, T: IntoIterator, Acc, R: Try<Output = Acc>>( - frontiter: &'a mut Option<T::IntoIter>, - fold: &'a mut impl FnMut(Acc, T::Item) -> R, - ) -> impl FnMut(Acc, T) -> R + 'a { - move |acc, x| { - let mut mid = x.into_iter(); - let r = mid.try_fold(acc, &mut *fold); - *frontiter = Some(mid); - r - } - } - - if let Some(ref mut front) = self.frontiter { - init = front.try_fold(init, &mut fold)?; + fn flatten<U: Iterator, Acc, R: Try<Output = Acc>>( + mut fold: impl FnMut(Acc, U::Item) -> R, + ) -> impl FnMut(Acc, &mut U) -> R { + move |acc, iter| iter.try_fold(acc, &mut fold) } - self.frontiter = None; - init = self.iter.try_fold(init, flatten(&mut self.frontiter, &mut fold))?; - self.frontiter = None; - - if let Some(ref mut back) = self.backiter { - init = back.try_fold(init, &mut fold)?; - } - self.backiter = None; - - try { init } + self.iter_try_fold(init, flatten(fold)) } #[inline] - fn fold<Acc, Fold>(self, mut init: Acc, mut fold: Fold) -> Acc + fn fold<Acc, Fold>(self, init: Acc, fold: Fold) -> Acc where Fold: FnMut(Acc, Self::Item) -> Acc, { #[inline] - fn flatten<T: IntoIterator, Acc>( - fold: &mut impl FnMut(Acc, T::Item) -> Acc, - ) -> impl FnMut(Acc, T) -> Acc + '_ { - move |acc, x| x.into_iter().fold(acc, &mut *fold) - } - - if let Some(front) = self.frontiter { - init = front.fold(init, &mut fold); - } - - init = self.iter.fold(init, flatten(&mut fold)); - - if let Some(back) = self.backiter { - init = back.fold(init, &mut fold); + fn flatten<U: Iterator, Acc>( + mut fold: impl FnMut(Acc, U::Item) -> Acc, + ) -> impl FnMut(Acc, U) -> Acc { + move |acc, iter| iter.fold(acc, &mut fold) } - init + self.iter_fold(init, flatten(fold)) } #[inline] #[rustc_inherit_overflow_checks] fn advance_by(&mut self, n: usize) -> Result<(), usize> { - let mut rem = n; - loop { - if let Some(ref mut front) = self.frontiter { - match front.advance_by(rem) { - ret @ Ok(_) => return ret, - Err(advanced) => rem -= advanced, - } - } - self.frontiter = match self.iter.next() { - Some(iterable) => Some(iterable.into_iter()), - _ => break, + #[inline] + #[rustc_inherit_overflow_checks] + fn advance<U: Iterator>(n: usize, iter: &mut U) -> ControlFlow<(), usize> { + match iter.advance_by(n) { + Ok(()) => ControlFlow::BREAK, + Err(advanced) => ControlFlow::Continue(n - advanced), } } - self.frontiter = None; - - if let Some(ref mut back) = self.backiter { - match back.advance_by(rem) { - ret @ Ok(_) => return ret, - Err(advanced) => rem -= advanced, - } + match self.iter_try_fold(n, advance) { + ControlFlow::Continue(remaining) if remaining > 0 => Err(n - remaining), + _ => Ok(()), } + } - if rem > 0 { - return Err(n - rem); + #[inline] + fn count(self) -> usize { + #[inline] + #[rustc_inherit_overflow_checks] + fn count<U: Iterator>(acc: usize, iter: U) -> usize { + acc + iter.count() } - self.backiter = None; + self.iter_fold(0, count) + } + + #[inline] + fn last(self) -> Option<Self::Item> { + #[inline] + fn last<U: Iterator>(last: Option<U::Item>, iter: U) -> Option<U::Item> { + iter.last().or(last) + } - Ok(()) + self.iter_fold(None, last) } } @@ -438,105 +591,53 @@ where } #[inline] - fn try_rfold<Acc, Fold, R>(&mut self, mut init: Acc, mut fold: Fold) -> R + fn try_rfold<Acc, Fold, R>(&mut self, init: Acc, fold: Fold) -> R where Self: Sized, Fold: FnMut(Acc, Self::Item) -> R, R: Try<Output = Acc>, { #[inline] - fn flatten<'a, T: IntoIterator, Acc, R: Try<Output = Acc>>( - backiter: &'a mut Option<T::IntoIter>, - fold: &'a mut impl FnMut(Acc, T::Item) -> R, - ) -> impl FnMut(Acc, T) -> R + 'a - where - T::IntoIter: DoubleEndedIterator, - { - move |acc, x| { - let mut mid = x.into_iter(); - let r = mid.try_rfold(acc, &mut *fold); - *backiter = Some(mid); - r - } + fn flatten<U: DoubleEndedIterator, Acc, R: Try<Output = Acc>>( + mut fold: impl FnMut(Acc, U::Item) -> R, + ) -> impl FnMut(Acc, &mut U) -> R { + move |acc, iter| iter.try_rfold(acc, &mut fold) } - if let Some(ref mut back) = self.backiter { - init = back.try_rfold(init, &mut fold)?; - } - self.backiter = None; - - init = self.iter.try_rfold(init, flatten(&mut self.backiter, &mut fold))?; - self.backiter = None; - - if let Some(ref mut front) = self.frontiter { - init = front.try_rfold(init, &mut fold)?; - } - self.frontiter = None; - - try { init } + self.iter_try_rfold(init, flatten(fold)) } #[inline] - fn rfold<Acc, Fold>(self, mut init: Acc, mut fold: Fold) -> Acc + fn rfold<Acc, Fold>(self, init: Acc, fold: Fold) -> Acc where Fold: FnMut(Acc, Self::Item) -> Acc, { #[inline] - fn flatten<T: IntoIterator, Acc>( - fold: &mut impl FnMut(Acc, T::Item) -> Acc, - ) -> impl FnMut(Acc, T) -> Acc + '_ - where - T::IntoIter: DoubleEndedIterator, - { - move |acc, x| x.into_iter().rfold(acc, &mut *fold) - } - - if let Some(back) = self.backiter { - init = back.rfold(init, &mut fold); + fn flatten<U: DoubleEndedIterator, Acc>( + mut fold: impl FnMut(Acc, U::Item) -> Acc, + ) -> impl FnMut(Acc, U) -> Acc { + move |acc, iter| iter.rfold(acc, &mut fold) } - init = self.iter.rfold(init, flatten(&mut fold)); - - if let Some(front) = self.frontiter { - init = front.rfold(init, &mut fold); - } - - init + self.iter_rfold(init, flatten(fold)) } #[inline] #[rustc_inherit_overflow_checks] fn advance_back_by(&mut self, n: usize) -> Result<(), usize> { - let mut rem = n; - loop { - if let Some(ref mut back) = self.backiter { - match back.advance_back_by(rem) { - ret @ Ok(_) => return ret, - Err(advanced) => rem -= advanced, - } - } - match self.iter.next_back() { - Some(iterable) => self.backiter = Some(iterable.into_iter()), - _ => break, - } - } - - self.backiter = None; - - if let Some(ref mut front) = self.frontiter { - match front.advance_back_by(rem) { - ret @ Ok(_) => return ret, - Err(advanced) => rem -= advanced, + #[inline] + #[rustc_inherit_overflow_checks] + fn advance<U: DoubleEndedIterator>(n: usize, iter: &mut U) -> ControlFlow<(), usize> { + match iter.advance_back_by(n) { + Ok(()) => ControlFlow::BREAK, + Err(advanced) => ControlFlow::Continue(n - advanced), } } - if rem > 0 { - return Err(n - rem); + match self.iter_try_rfold(n, advance) { + ControlFlow::Continue(remaining) if remaining > 0 => Err(n - remaining), + _ => Ok(()), } - - self.frontiter = None; - - Ok(()) } } diff --git a/library/core/src/iter/adapters/map_while.rs b/library/core/src/iter/adapters/map_while.rs index 1e8d6bf3e..fbdeca4d4 100644 --- a/library/core/src/iter/adapters/map_while.rs +++ b/library/core/src/iter/adapters/map_while.rs @@ -64,19 +64,7 @@ where .into_try() } - #[inline] - fn fold<Acc, Fold>(mut self, init: Acc, fold: Fold) -> Acc - where - Self: Sized, - Fold: FnMut(Acc, Self::Item) -> Acc, - { - #[inline] - fn ok<B, T>(mut f: impl FnMut(B, T) -> B) -> impl FnMut(B, T) -> Result<B, !> { - move |acc, x| Ok(f(acc, x)) - } - - self.try_fold(init, ok(fold)).unwrap() - } + impl_fold_via_try_fold! { fold -> try_fold } } #[unstable(issue = "none", feature = "inplace_iteration")] diff --git a/library/core/src/iter/adapters/mod.rs b/library/core/src/iter/adapters/mod.rs index 916a26e24..8cc2b7cec 100644 --- a/library/core/src/iter/adapters/mod.rs +++ b/library/core/src/iter/adapters/mod.rs @@ -1,6 +1,7 @@ use crate::iter::{InPlaceIterable, Iterator}; -use crate::ops::{ChangeOutputType, ControlFlow, FromResidual, NeverShortCircuit, Residual, Try}; +use crate::ops::{ChangeOutputType, ControlFlow, FromResidual, Residual, Try}; +mod array_chunks; mod by_ref_sized; mod chain; mod cloned; @@ -32,6 +33,9 @@ pub use self::{ scan::Scan, skip::Skip, skip_while::SkipWhile, take::Take, take_while::TakeWhile, zip::Zip, }; +#[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "100450")] +pub use self::array_chunks::ArrayChunks; + #[unstable(feature = "std_internals", issue = "none")] pub use self::by_ref_sized::ByRefSized; @@ -199,13 +203,7 @@ where .into_try() } - fn fold<B, F>(mut self, init: B, fold: F) -> B - where - Self: Sized, - F: FnMut(B, Self::Item) -> B, - { - self.try_fold(init, NeverShortCircuit::wrap_mut_2(fold)).0 - } + impl_fold_via_try_fold! { fold -> try_fold } } #[unstable(issue = "none", feature = "inplace_iteration")] diff --git a/library/core/src/iter/adapters/scan.rs b/library/core/src/iter/adapters/scan.rs index 80bfd2231..62470512c 100644 --- a/library/core/src/iter/adapters/scan.rs +++ b/library/core/src/iter/adapters/scan.rs @@ -74,19 +74,7 @@ where self.iter.try_fold(init, scan(state, f, fold)).into_try() } - #[inline] - fn fold<Acc, Fold>(mut self, init: Acc, fold: Fold) -> Acc - where - Self: Sized, - Fold: FnMut(Acc, Self::Item) -> Acc, - { - #[inline] - fn ok<B, T>(mut f: impl FnMut(B, T) -> B) -> impl FnMut(B, T) -> Result<B, !> { - move |acc, x| Ok(f(acc, x)) - } - - self.try_fold(init, ok(fold)).unwrap() - } + impl_fold_via_try_fold! { fold -> try_fold } } #[unstable(issue = "none", feature = "inplace_iteration")] diff --git a/library/core/src/iter/adapters/skip.rs b/library/core/src/iter/adapters/skip.rs index 2c283100f..c6334880d 100644 --- a/library/core/src/iter/adapters/skip.rs +++ b/library/core/src/iter/adapters/skip.rs @@ -33,21 +33,32 @@ where #[inline] fn next(&mut self) -> Option<I::Item> { if unlikely(self.n > 0) { - self.iter.nth(crate::mem::take(&mut self.n) - 1)?; + self.iter.nth(crate::mem::take(&mut self.n)) + } else { + self.iter.next() } - self.iter.next() } #[inline] fn nth(&mut self, n: usize) -> Option<I::Item> { - // Can't just add n + self.n due to overflow. if self.n > 0 { - let to_skip = self.n; - self.n = 0; - // nth(n) skips n+1 - self.iter.nth(to_skip - 1)?; + let skip: usize = crate::mem::take(&mut self.n); + // Checked add to handle overflow case. + let n = match skip.checked_add(n) { + Some(nth) => nth, + None => { + // In case of overflow, load skip value, before loading `n`. + // Because the amount of elements to iterate is beyond `usize::MAX`, this + // is split into two `nth` calls where the `skip` `nth` call is discarded. + self.iter.nth(skip - 1)?; + n + } + }; + // Load nth element including skip. + self.iter.nth(n) + } else { + self.iter.nth(n) } - self.iter.nth(n) } #[inline] @@ -195,17 +206,7 @@ where if n == 0 { try { init } } else { self.iter.try_rfold(init, check(n, fold)).into_try() } } - fn rfold<Acc, Fold>(mut self, init: Acc, fold: Fold) -> Acc - where - Fold: FnMut(Acc, Self::Item) -> Acc, - { - #[inline] - fn ok<Acc, T>(mut f: impl FnMut(Acc, T) -> Acc) -> impl FnMut(Acc, T) -> Result<Acc, !> { - move |acc, x| Ok(f(acc, x)) - } - - self.try_rfold(init, ok(fold)).unwrap() - } + impl_fold_via_try_fold! { rfold -> try_rfold } #[inline] fn advance_back_by(&mut self, n: usize) -> Result<(), usize> { diff --git a/library/core/src/iter/adapters/take.rs b/library/core/src/iter/adapters/take.rs index 2962e0104..58a0b9d7b 100644 --- a/library/core/src/iter/adapters/take.rs +++ b/library/core/src/iter/adapters/take.rs @@ -98,19 +98,7 @@ where } } - #[inline] - fn fold<Acc, Fold>(mut self, init: Acc, fold: Fold) -> Acc - where - Self: Sized, - Fold: FnMut(Acc, Self::Item) -> Acc, - { - #[inline] - fn ok<B, T>(mut f: impl FnMut(B, T) -> B) -> impl FnMut(B, T) -> Result<B, !> { - move |acc, x| Ok(f(acc, x)) - } - - self.try_fold(init, ok(fold)).unwrap() - } + impl_fold_via_try_fold! { fold -> try_fold } #[inline] #[rustc_inherit_overflow_checks] diff --git a/library/core/src/iter/adapters/take_while.rs b/library/core/src/iter/adapters/take_while.rs index ded216da9..ec66dc3ae 100644 --- a/library/core/src/iter/adapters/take_while.rs +++ b/library/core/src/iter/adapters/take_while.rs @@ -94,19 +94,7 @@ where } } - #[inline] - fn fold<Acc, Fold>(mut self, init: Acc, fold: Fold) -> Acc - where - Self: Sized, - Fold: FnMut(Acc, Self::Item) -> Acc, - { - #[inline] - fn ok<B, T>(mut f: impl FnMut(B, T) -> B) -> impl FnMut(B, T) -> Result<B, !> { - move |acc, x| Ok(f(acc, x)) - } - - self.try_fold(init, ok(fold)).unwrap() - } + impl_fold_via_try_fold! { fold -> try_fold } } #[stable(feature = "fused", since = "1.26.0")] diff --git a/library/core/src/iter/mod.rs b/library/core/src/iter/mod.rs index d5c6aed5b..ef0f39782 100644 --- a/library/core/src/iter/mod.rs +++ b/library/core/src/iter/mod.rs @@ -352,6 +352,29 @@ #![stable(feature = "rust1", since = "1.0.0")] +// This needs to be up here in order to be usable in the child modules +macro_rules! impl_fold_via_try_fold { + (fold -> try_fold) => { + impl_fold_via_try_fold! { @internal fold -> try_fold } + }; + (rfold -> try_rfold) => { + impl_fold_via_try_fold! { @internal rfold -> try_rfold } + }; + (@internal $fold:ident -> $try_fold:ident) => { + #[inline] + fn $fold<AAA, FFF>(mut self, init: AAA, mut fold: FFF) -> AAA + where + FFF: FnMut(AAA, Self::Item) -> AAA, + { + use crate::const_closure::ConstFnMutClosure; + use crate::ops::NeverShortCircuit; + + let fold = ConstFnMutClosure::new(&mut fold, NeverShortCircuit::wrap_mut_2_imp); + self.$try_fold(init, fold).0 + } + }; +} + #[stable(feature = "rust1", since = "1.0.0")] pub use self::traits::Iterator; @@ -398,6 +421,8 @@ pub use self::traits::{ #[stable(feature = "iter_zip", since = "1.59.0")] pub use self::adapters::zip; +#[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "100450")] +pub use self::adapters::ArrayChunks; #[unstable(feature = "std_internals", issue = "none")] pub use self::adapters::ByRefSized; #[stable(feature = "iter_cloned", since = "1.1.0")] diff --git a/library/core/src/iter/range.rs b/library/core/src/iter/range.rs index f7aeee8c9..ac7b389b1 100644 --- a/library/core/src/iter/range.rs +++ b/library/core/src/iter/range.rs @@ -1150,19 +1150,7 @@ impl<A: Step> Iterator for ops::RangeInclusive<A> { self.spec_try_fold(init, f) } - #[inline] - fn fold<B, F>(mut self, init: B, f: F) -> B - where - Self: Sized, - F: FnMut(B, Self::Item) -> B, - { - #[inline] - fn ok<B, T>(mut f: impl FnMut(B, T) -> B) -> impl FnMut(B, T) -> Result<B, !> { - move |acc, x| Ok(f(acc, x)) - } - - self.try_fold(init, ok(f)).unwrap() - } + impl_fold_via_try_fold! { fold -> try_fold } #[inline] fn last(mut self) -> Option<A> { @@ -1230,19 +1218,7 @@ impl<A: Step> DoubleEndedIterator for ops::RangeInclusive<A> { self.spec_try_rfold(init, f) } - #[inline] - fn rfold<B, F>(mut self, init: B, f: F) -> B - where - Self: Sized, - F: FnMut(B, Self::Item) -> B, - { - #[inline] - fn ok<B, T>(mut f: impl FnMut(B, T) -> B) -> impl FnMut(B, T) -> Result<B, !> { - move |acc, x| Ok(f(acc, x)) - } - - self.try_rfold(init, ok(f)).unwrap() - } + impl_fold_via_try_fold! { rfold -> try_rfold } } // Safety: See above implementation for `ops::Range<A>` diff --git a/library/core/src/iter/traits/collect.rs b/library/core/src/iter/traits/collect.rs index 12ca508be..e099700e3 100644 --- a/library/core/src/iter/traits/collect.rs +++ b/library/core/src/iter/traits/collect.rs @@ -228,6 +228,7 @@ pub trait FromIterator<A>: Sized { #[rustc_diagnostic_item = "IntoIterator"] #[rustc_skip_array_during_method_dispatch] #[stable(feature = "rust1", since = "1.0.0")] +#[const_trait] pub trait IntoIterator { /// The type of the elements being iterated over. #[stable(feature = "rust1", since = "1.0.0")] @@ -263,7 +264,7 @@ pub trait IntoIterator { #[rustc_const_unstable(feature = "const_intoiterator_identity", issue = "90603")] #[stable(feature = "rust1", since = "1.0.0")] -impl<I: ~const Iterator> const IntoIterator for I { +impl<I: Iterator> const IntoIterator for I { type Item = I::Item; type IntoIter = I; diff --git a/library/core/src/iter/traits/iterator.rs b/library/core/src/iter/traits/iterator.rs index 275412b57..789a87968 100644 --- a/library/core/src/iter/traits/iterator.rs +++ b/library/core/src/iter/traits/iterator.rs @@ -5,7 +5,7 @@ use crate::ops::{ChangeOutputType, ControlFlow, FromResidual, Residual, Try}; use super::super::try_process; use super::super::ByRefSized; use super::super::TrustedRandomAccessNoCoerce; -use super::super::{Chain, Cloned, Copied, Cycle, Enumerate, Filter, FilterMap, Fuse}; +use super::super::{ArrayChunks, Chain, Cloned, Copied, Cycle, Enumerate, Filter, FilterMap, Fuse}; use super::super::{FlatMap, Flatten}; use super::super::{FromIterator, Intersperse, IntersperseWith, Product, Sum, Zip}; use super::super::{ @@ -692,7 +692,7 @@ pub trait Iterator { /// assert_eq!(it.next(), Some(NotClone(99))); // The separator. /// assert_eq!(it.next(), Some(NotClone(1))); // The next element from `v`. /// assert_eq!(it.next(), Some(NotClone(99))); // The separator. - /// assert_eq!(it.next(), Some(NotClone(2))); // The last element from from `v`. + /// assert_eq!(it.next(), Some(NotClone(2))); // The last element from `v`. /// assert_eq!(it.next(), None); // The iterator is finished. /// ``` /// @@ -2431,22 +2431,13 @@ pub trait Iterator { /// /// # Example /// - /// Find the maximum value: - /// /// ``` - /// fn find_max<I>(iter: I) -> Option<I::Item> - /// where I: Iterator, - /// I::Item: Ord, - /// { - /// iter.reduce(|accum, item| { - /// if accum >= item { accum } else { item } - /// }) - /// } - /// let a = [10, 20, 5, -23, 0]; - /// let b: [u32; 0] = []; + /// let reduced: i32 = (1..10).reduce(|acc, e| acc + e).unwrap(); + /// assert_eq!(reduced, 45); /// - /// assert_eq!(find_max(a.iter()), Some(&20)); - /// assert_eq!(find_max(b.iter()), None); + /// // Which is equivalent to doing it with `fold`: + /// let folded: i32 = (1..10).fold(0, |acc, e| acc + e); + /// assert_eq!(reduced, folded); /// ``` #[inline] #[stable(feature = "iterator_fold_self", since = "1.51.0")] @@ -2906,14 +2897,14 @@ pub trait Iterator { /// Stopping at the first `true`: /// /// ``` - /// let a = [1, 2, 3]; + /// let a = [-1, 2, 3, 4]; /// /// let mut iter = a.iter(); /// - /// assert_eq!(iter.rposition(|&x| x == 2), Some(1)); + /// assert_eq!(iter.rposition(|&x| x >= 2), Some(3)); /// /// // we can still use `iter`, as there are more elements. - /// assert_eq!(iter.next(), Some(&1)); + /// assert_eq!(iter.next(), Some(&-1)); /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] @@ -3316,6 +3307,49 @@ pub trait Iterator { Cycle::new(self) } + /// Returns an iterator over `N` elements of the iterator at a time. + /// + /// The chunks do not overlap. If `N` does not divide the length of the + /// iterator, then the last up to `N-1` elements will be omitted and can be + /// retrieved from the [`.into_remainder()`][ArrayChunks::into_remainder] + /// function of the iterator. + /// + /// # Panics + /// + /// Panics if `N` is 0. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(iter_array_chunks)] + /// + /// let mut iter = "lorem".chars().array_chunks(); + /// assert_eq!(iter.next(), Some(['l', 'o'])); + /// assert_eq!(iter.next(), Some(['r', 'e'])); + /// assert_eq!(iter.next(), None); + /// assert_eq!(iter.into_remainder().unwrap().as_slice(), &['m']); + /// ``` + /// + /// ``` + /// #![feature(iter_array_chunks)] + /// + /// let data = [1, 1, 2, -2, 6, 0, 3, 1]; + /// // ^-----^ ^------^ + /// for [x, y, z] in data.iter().array_chunks() { + /// assert_eq!(x + y + z, 4); + /// } + /// ``` + #[track_caller] + #[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "100450")] + fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N> + where + Self: Sized, + { + ArrayChunks::new(self) + } + /// Sums the elements of an iterator. /// /// Takes each element, adds them together, and returns the result. @@ -3418,36 +3452,27 @@ pub trait Iterator { /// assert_eq!(xs.iter().cmp_by(&ys, |&x, &y| (2 * x).cmp(&y)), Ordering::Greater); /// ``` #[unstable(feature = "iter_order_by", issue = "64295")] - fn cmp_by<I, F>(mut self, other: I, mut cmp: F) -> Ordering + fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering where Self: Sized, I: IntoIterator, F: FnMut(Self::Item, I::Item) -> Ordering, { - let mut other = other.into_iter(); - - loop { - let x = match self.next() { - None => { - if other.next().is_none() { - return Ordering::Equal; - } else { - return Ordering::Less; - } - } - Some(val) => val, - }; - - let y = match other.next() { - None => return Ordering::Greater, - Some(val) => val, - }; - - match cmp(x, y) { - Ordering::Equal => (), - non_eq => return non_eq, + #[inline] + fn compare<X, Y, F>(mut cmp: F) -> impl FnMut(X, Y) -> ControlFlow<Ordering> + where + F: FnMut(X, Y) -> Ordering, + { + move |x, y| match cmp(x, y) { + Ordering::Equal => ControlFlow::CONTINUE, + non_eq => ControlFlow::Break(non_eq), } } + + match iter_compare(self, other.into_iter(), compare(cmp)) { + ControlFlow::Continue(ord) => ord, + ControlFlow::Break(ord) => ord, + } } /// [Lexicographically](Ord#lexicographical-comparison) compares the elements of this [`Iterator`] with those @@ -3503,36 +3528,27 @@ pub trait Iterator { /// ); /// ``` #[unstable(feature = "iter_order_by", issue = "64295")] - fn partial_cmp_by<I, F>(mut self, other: I, mut partial_cmp: F) -> Option<Ordering> + fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering> where Self: Sized, I: IntoIterator, F: FnMut(Self::Item, I::Item) -> Option<Ordering>, { - let mut other = other.into_iter(); - - loop { - let x = match self.next() { - None => { - if other.next().is_none() { - return Some(Ordering::Equal); - } else { - return Some(Ordering::Less); - } - } - Some(val) => val, - }; - - let y = match other.next() { - None => return Some(Ordering::Greater), - Some(val) => val, - }; - - match partial_cmp(x, y) { - Some(Ordering::Equal) => (), - non_eq => return non_eq, + #[inline] + fn compare<X, Y, F>(mut partial_cmp: F) -> impl FnMut(X, Y) -> ControlFlow<Option<Ordering>> + where + F: FnMut(X, Y) -> Option<Ordering>, + { + move |x, y| match partial_cmp(x, y) { + Some(Ordering::Equal) => ControlFlow::CONTINUE, + non_eq => ControlFlow::Break(non_eq), } } + + match iter_compare(self, other.into_iter(), compare(partial_cmp)) { + ControlFlow::Continue(ord) => Some(ord), + ControlFlow::Break(ord) => ord, + } } /// Determines if the elements of this [`Iterator`] are equal to those of @@ -3570,29 +3586,26 @@ pub trait Iterator { /// assert!(xs.iter().eq_by(&ys, |&x, &y| x * x == y)); /// ``` #[unstable(feature = "iter_order_by", issue = "64295")] - fn eq_by<I, F>(mut self, other: I, mut eq: F) -> bool + fn eq_by<I, F>(self, other: I, eq: F) -> bool where Self: Sized, I: IntoIterator, F: FnMut(Self::Item, I::Item) -> bool, { - let mut other = other.into_iter(); - - loop { - let x = match self.next() { - None => return other.next().is_none(), - Some(val) => val, - }; - - let y = match other.next() { - None => return false, - Some(val) => val, - }; - - if !eq(x, y) { - return false; + #[inline] + fn compare<X, Y, F>(mut eq: F) -> impl FnMut(X, Y) -> ControlFlow<()> + where + F: FnMut(X, Y) -> bool, + { + move |x, y| { + if eq(x, y) { ControlFlow::CONTINUE } else { ControlFlow::BREAK } } } + + match iter_compare(self, other.into_iter(), compare(eq)) { + ControlFlow::Continue(ord) => ord == Ordering::Equal, + ControlFlow::Break(()) => false, + } } /// Determines if the elements of this [`Iterator`] are unequal to those of @@ -3817,6 +3830,46 @@ pub trait Iterator { } } +/// Compares two iterators element-wise using the given function. +/// +/// If `ControlFlow::CONTINUE` is returned from the function, the comparison moves on to the next +/// elements of both iterators. Returning `ControlFlow::Break(x)` short-circuits the iteration and +/// returns `ControlFlow::Break(x)`. If one of the iterators runs out of elements, +/// `ControlFlow::Continue(ord)` is returned where `ord` is the result of comparing the lengths of +/// the iterators. +/// +/// Isolates the logic shared by ['cmp_by'](Iterator::cmp_by), +/// ['partial_cmp_by'](Iterator::partial_cmp_by), and ['eq_by'](Iterator::eq_by). +#[inline] +fn iter_compare<A, B, F, T>(mut a: A, mut b: B, f: F) -> ControlFlow<T, Ordering> +where + A: Iterator, + B: Iterator, + F: FnMut(A::Item, B::Item) -> ControlFlow<T>, +{ + #[inline] + fn compare<'a, B, X, T>( + b: &'a mut B, + mut f: impl FnMut(X, B::Item) -> ControlFlow<T> + 'a, + ) -> impl FnMut(X) -> ControlFlow<ControlFlow<T, Ordering>> + 'a + where + B: Iterator, + { + move |x| match b.next() { + None => ControlFlow::Break(ControlFlow::Continue(Ordering::Greater)), + Some(y) => f(x, y).map_break(ControlFlow::Break), + } + } + + match a.try_for_each(compare(&mut b, f)) { + ControlFlow::Continue(()) => ControlFlow::Continue(match b.next() { + None => Ordering::Equal, + Some(_) => Ordering::Less, + }), + ControlFlow::Break(x) => x, + } +} + #[stable(feature = "rust1", since = "1.0.0")] impl<I: Iterator + ?Sized> Iterator for &mut I { type Item = I::Item; diff --git a/library/core/src/lazy.rs b/library/core/src/lazy.rs deleted file mode 100644 index f8c06c3f9..000000000 --- a/library/core/src/lazy.rs +++ /dev/null @@ -1 +0,0 @@ -//! Lazy values and one-time initialization of static data. diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs index 24742bb49..659409557 100644 --- a/library/core/src/lib.rs +++ b/library/core/src/lib.rs @@ -93,6 +93,7 @@ #![warn(missing_debug_implementations)] #![warn(missing_docs)] #![allow(explicit_outlives_requirements)] +#![allow(incomplete_features)] // // Library features: #![feature(const_align_offset)] @@ -113,6 +114,7 @@ #![feature(const_fmt_arguments_new)] #![feature(const_heap)] #![feature(const_convert)] +#![feature(const_index_range_slice_index)] #![feature(const_inherent_unchecked_arith)] #![feature(const_int_unchecked_arith)] #![feature(const_intrinsic_forget)] @@ -130,25 +132,30 @@ #![feature(const_replace)] #![feature(const_ptr_as_ref)] #![feature(const_ptr_is_null)] -#![feature(const_ptr_offset_from)] #![feature(const_ptr_read)] #![feature(const_ptr_write)] #![feature(const_raw_ptr_comparison)] #![feature(const_size_of_val)] #![feature(const_slice_from_raw_parts_mut)] #![feature(const_slice_ptr_len)] +#![feature(const_slice_split_at_mut)] #![feature(const_str_from_utf8_unchecked_mut)] #![feature(const_swap)] #![feature(const_trait_impl)] +#![feature(const_try)] #![feature(const_type_id)] #![feature(const_type_name)] #![feature(const_default_impls)] +#![feature(const_unicode_case_lookup)] #![feature(const_unsafecell_get_mut)] +#![feature(const_waker)] #![feature(core_panic)] #![feature(duration_consts_float)] #![feature(maybe_uninit_uninit_array)] +#![feature(ptr_alignment_type)] #![feature(ptr_metadata)] #![feature(slice_ptr_get)] +#![feature(slice_split_at_unchecked)] #![feature(str_internals)] #![feature(utf16_extra)] #![feature(utf16_extra_const)] @@ -157,13 +164,17 @@ #![feature(const_slice_from_ref)] #![feature(const_slice_index)] #![feature(const_is_char_boundary)] +#![feature(const_cstr_methods)] +#![feature(is_ascii_octdigit)] // // Language features: #![feature(abi_unadjusted)] +#![feature(adt_const_params)] #![feature(allow_internal_unsafe)] #![feature(allow_internal_unstable)] #![feature(associated_type_bounds)] #![feature(auto_traits)] +#![feature(c_unwind)] #![feature(cfg_sanitize)] #![feature(cfg_target_has_atomic)] #![feature(cfg_target_has_atomic_equal_alignment)] @@ -181,13 +192,13 @@ #![feature(extern_types)] #![feature(fundamental)] #![feature(if_let_guard)] +#![feature(inline_const)] #![feature(intra_doc_pointers)] #![feature(intrinsics)] #![feature(lang_items)] #![feature(link_llvm_intrinsics)] #![feature(macro_metavar_expr)] #![feature(min_specialization)] -#![feature(mixed_integer_ops)] #![feature(must_not_suspend)] #![feature(negative_impls)] #![feature(never_type)] @@ -201,12 +212,14 @@ #![feature(simd_ffi)] #![feature(staged_api)] #![feature(stmt_expr_attributes)] +#![feature(target_feature_11)] #![feature(trait_alias)] #![feature(transparent_unions)] #![feature(try_blocks)] #![feature(unboxed_closures)] #![feature(unsized_fn_params)] #![feature(asm_const)] +#![feature(const_transmute_copy)] // // Target features: #![feature(arm_target_feature)] @@ -216,6 +229,7 @@ #![feature(hexagon_target_feature)] #![feature(mips_target_feature)] #![feature(powerpc_target_feature)] +#![feature(riscv_target_feature)] #![feature(rtm_target_feature)] #![feature(sse4a_target_feature)] #![feature(tbm_target_feature)] @@ -302,6 +316,7 @@ pub mod clone; pub mod cmp; pub mod convert; pub mod default; +pub mod error; pub mod marker; pub mod ops; @@ -317,8 +332,6 @@ pub mod cell; pub mod char; pub mod ffi; pub mod iter; -#[unstable(feature = "once_cell", issue = "74465")] -pub mod lazy; pub mod option; pub mod panic; pub mod panicking; @@ -347,6 +360,8 @@ mod bool; mod tuple; mod unit; +mod const_closure; + #[stable(feature = "core_primitive", since = "1.43.0")] pub mod primitive; diff --git a/library/core/src/macros/mod.rs b/library/core/src/macros/mod.rs index 3a115a8b8..fd96e1ff7 100644 --- a/library/core/src/macros/mod.rs +++ b/library/core/src/macros/mod.rs @@ -350,10 +350,12 @@ macro_rules! matches { /// Unwraps a result or propagates its error. /// -/// The `?` operator was added to replace `try!` and should be used instead. -/// Furthermore, `try` is a reserved word in Rust 2018, so if you must use -/// it, you will need to use the [raw-identifier syntax][ris]: `r#try`. +/// The [`?` operator][propagating-errors] was added to replace `try!` +/// and should be used instead. Furthermore, `try` is a reserved word +/// in Rust 2018, so if you must use it, you will need to use the +/// [raw-identifier syntax][ris]: `r#try`. /// +/// [propagating-errors]: https://doc.rust-lang.org/book/ch09-02-recoverable-errors-with-result.html#a-shortcut-for-propagating-errors-the--operator /// [ris]: https://doc.rust-lang.org/nightly/rust-by-example/compatibility/raw_identifiers.html /// /// `try!` matches the given [`Result`]. In case of the `Ok` variant, the @@ -457,11 +459,12 @@ macro_rules! r#try { /// /// A module can import both `std::fmt::Write` and `std::io::Write` and call `write!` on objects /// implementing either, as objects do not typically implement both. However, the module must -/// import the traits qualified so their names do not conflict: +/// avoid conflict between the trait names, such as by importing them as `_` or otherwise renaming +/// them: /// /// ``` -/// use std::fmt::Write as FmtWrite; -/// use std::io::Write as IoWrite; +/// use std::fmt::Write as _; +/// use std::io::Write as _; /// /// fn main() -> Result<(), Box<dyn std::error::Error>> { /// let mut s = String::new(); @@ -474,6 +477,23 @@ macro_rules! r#try { /// } /// ``` /// +/// If you also need the trait names themselves, such as to implement one or both on your types, +/// import the containing module and then name them with a prefix: +/// +/// ``` +/// # #![allow(unused_imports)] +/// use std::fmt::{self, Write as _}; +/// use std::io::{self, Write as _}; +/// +/// struct Example; +/// +/// impl fmt::Write for Example { +/// fn write_str(&mut self, _s: &str) -> core::fmt::Result { +/// unimplemented!(); +/// } +/// } +/// ``` +/// /// Note: This macro can be used in `no_std` setups as well. /// In a `no_std` setup you are responsible for the implementation details of the components. /// @@ -526,25 +546,6 @@ macro_rules! write { /// Ok(()) /// } /// ``` -/// -/// A module can import both `std::fmt::Write` and `std::io::Write` and call `write!` on objects -/// implementing either, as objects do not typically implement both. However, the module must -/// import the traits qualified so their names do not conflict: -/// -/// ``` -/// use std::fmt::Write as FmtWrite; -/// use std::io::Write as IoWrite; -/// -/// fn main() -> Result<(), Box<dyn std::error::Error>> { -/// let mut s = String::new(); -/// let mut v = Vec::new(); -/// -/// writeln!(&mut s, "{} {}", "abc", 123)?; // uses fmt::Write::write_fmt -/// writeln!(&mut v, "s = {:?}", s)?; // uses io::Write::write_fmt -/// assert_eq!(v, b"s = \"abc 123\\n\"\n"); -/// Ok(()) -/// } -/// ``` #[macro_export] #[stable(feature = "rust1", since = "1.0.0")] #[cfg_attr(not(test), rustc_diagnostic_item = "writeln_macro")] @@ -1015,7 +1016,7 @@ pub(crate) mod builtin { /// Concatenates literals into a byte slice. /// /// This macro takes any number of comma-separated literals, and concatenates them all into - /// one, yielding an expression of type `&[u8, _]`, which represents all of the literals + /// one, yielding an expression of type `&[u8; _]`, which represents all of the literals /// concatenated left-to-right. The literals passed can be any combination of: /// /// - byte literals (`b'r'`) diff --git a/library/core/src/marker.rs b/library/core/src/marker.rs index 2c5789795..ae4ebf444 100644 --- a/library/core/src/marker.rs +++ b/library/core/src/marker.rs @@ -44,6 +44,12 @@ impl<T: ?Sized> !Send for *const T {} #[stable(feature = "rust1", since = "1.0.0")] impl<T: ?Sized> !Send for *mut T {} +// Most instances arise automatically, but this instance is needed to link up `T: Sync` with +// `&T: Send` (and it also removes the unsound default instance `T Send` -> `&T: Send` that would +// otherwise exist). +#[stable(feature = "rust1", since = "1.0.0")] +unsafe impl<T: Sync + ?Sized> Send for &T {} + /// Types with a constant size known at compile time. /// /// All type parameters have an implicit bound of `Sized`. The special syntax @@ -81,6 +87,7 @@ impl<T: ?Sized> !Send for *mut T {} /// ``` /// /// [trait object]: ../../book/ch17-02-trait-objects.html +#[doc(alias = "?", alias = "?Sized")] #[stable(feature = "rust1", since = "1.0.0")] #[lang = "sized"] #[rustc_on_unimplemented( @@ -343,7 +350,7 @@ pub trait StructuralEq { /// If you try to implement `Copy` on a struct or enum containing non-`Copy` data, you will get /// the error [E0204]. /// -/// [E0204]: ../../error-index.html#E0204 +/// [E0204]: ../../error_codes/E0204.html /// /// ## When *should* my type be `Copy`? /// @@ -482,64 +489,6 @@ impl<T: ?Sized> !Sync for *const T {} #[stable(feature = "rust1", since = "1.0.0")] impl<T: ?Sized> !Sync for *mut T {} -macro_rules! impls { - ($t: ident) => { - #[stable(feature = "rust1", since = "1.0.0")] - impl<T: ?Sized> Hash for $t<T> { - #[inline] - fn hash<H: Hasher>(&self, _: &mut H) {} - } - - #[stable(feature = "rust1", since = "1.0.0")] - impl<T: ?Sized> cmp::PartialEq for $t<T> { - fn eq(&self, _other: &$t<T>) -> bool { - true - } - } - - #[stable(feature = "rust1", since = "1.0.0")] - impl<T: ?Sized> cmp::Eq for $t<T> {} - - #[stable(feature = "rust1", since = "1.0.0")] - impl<T: ?Sized> cmp::PartialOrd for $t<T> { - fn partial_cmp(&self, _other: &$t<T>) -> Option<cmp::Ordering> { - Option::Some(cmp::Ordering::Equal) - } - } - - #[stable(feature = "rust1", since = "1.0.0")] - impl<T: ?Sized> cmp::Ord for $t<T> { - fn cmp(&self, _other: &$t<T>) -> cmp::Ordering { - cmp::Ordering::Equal - } - } - - #[stable(feature = "rust1", since = "1.0.0")] - impl<T: ?Sized> Copy for $t<T> {} - - #[stable(feature = "rust1", since = "1.0.0")] - impl<T: ?Sized> Clone for $t<T> { - fn clone(&self) -> Self { - Self - } - } - - #[stable(feature = "rust1", since = "1.0.0")] - #[rustc_const_unstable(feature = "const_default_impls", issue = "87864")] - impl<T: ?Sized> const Default for $t<T> { - fn default() -> Self { - Self - } - } - - #[unstable(feature = "structural_match", issue = "31434")] - impl<T: ?Sized> StructuralPartialEq for $t<T> {} - - #[unstable(feature = "structural_match", issue = "31434")] - impl<T: ?Sized> StructuralEq for $t<T> {} - }; -} - /// Zero-sized type used to mark things that "act like" they own a `T`. /// /// Adding a `PhantomData<T>` field to your type tells the compiler that your @@ -677,15 +626,60 @@ macro_rules! impls { #[stable(feature = "rust1", since = "1.0.0")] pub struct PhantomData<T: ?Sized>; -impls! { PhantomData } +#[stable(feature = "rust1", since = "1.0.0")] +impl<T: ?Sized> Hash for PhantomData<T> { + #[inline] + fn hash<H: Hasher>(&self, _: &mut H) {} +} -mod impls { - #[stable(feature = "rust1", since = "1.0.0")] - unsafe impl<T: Sync + ?Sized> Send for &T {} - #[stable(feature = "rust1", since = "1.0.0")] - unsafe impl<T: Send + ?Sized> Send for &mut T {} +#[stable(feature = "rust1", since = "1.0.0")] +impl<T: ?Sized> cmp::PartialEq for PhantomData<T> { + fn eq(&self, _other: &PhantomData<T>) -> bool { + true + } } +#[stable(feature = "rust1", since = "1.0.0")] +impl<T: ?Sized> cmp::Eq for PhantomData<T> {} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<T: ?Sized> cmp::PartialOrd for PhantomData<T> { + fn partial_cmp(&self, _other: &PhantomData<T>) -> Option<cmp::Ordering> { + Option::Some(cmp::Ordering::Equal) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<T: ?Sized> cmp::Ord for PhantomData<T> { + fn cmp(&self, _other: &PhantomData<T>) -> cmp::Ordering { + cmp::Ordering::Equal + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<T: ?Sized> Copy for PhantomData<T> {} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<T: ?Sized> Clone for PhantomData<T> { + fn clone(&self) -> Self { + Self + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +#[rustc_const_unstable(feature = "const_default_impls", issue = "87864")] +impl<T: ?Sized> const Default for PhantomData<T> { + fn default() -> Self { + Self + } +} + +#[unstable(feature = "structural_match", issue = "31434")] +impl<T: ?Sized> StructuralPartialEq for PhantomData<T> {} + +#[unstable(feature = "structural_match", issue = "31434")] +impl<T: ?Sized> StructuralEq for PhantomData<T> {} + /// Compiler-internal trait used to indicate the type of enum discriminants. /// /// This trait is automatically implemented for every type and does not add any @@ -798,8 +792,18 @@ impl<T: ?Sized> Unpin for *mut T {} #[unstable(feature = "const_trait_impl", issue = "67792")] #[lang = "destruct"] #[rustc_on_unimplemented(message = "can't drop `{Self}`", append_const_msg)] +#[const_trait] pub trait Destruct {} +/// A marker for tuple types. +/// +/// The implementation of this trait is built-in and cannot be implemented +/// for any user type. +#[unstable(feature = "tuple_trait", issue = "none")] +#[lang = "tuple_trait"] +#[rustc_on_unimplemented(message = "`{Self}` is not a tuple")] +pub trait Tuple {} + /// Implementations of `Copy` for primitive types. /// /// Implementations that cannot be described in Rust diff --git a/library/core/src/mem/maybe_uninit.rs b/library/core/src/mem/maybe_uninit.rs index b4ea53608..7757c95de 100644 --- a/library/core/src/mem/maybe_uninit.rs +++ b/library/core/src/mem/maybe_uninit.rs @@ -54,9 +54,6 @@ use crate::slice; /// // The equivalent code with `MaybeUninit<i32>`: /// let x: i32 = unsafe { MaybeUninit::uninit().assume_init() }; // undefined behavior! ⚠️ /// ``` -/// (Notice that the rules around uninitialized integers are not finalized yet, but -/// until they are, it is advisable to avoid them.) -/// /// On top of that, remember that most types have additional invariants beyond merely /// being considered initialized at the type level. For example, a `1`-initialized [`Vec<T>`] /// is considered initialized (under the current implementation; this does not constitute @@ -130,11 +127,8 @@ use crate::slice; /// MaybeUninit::uninit().assume_init() /// }; /// -/// // Dropping a `MaybeUninit` does nothing. Thus using raw pointer -/// // assignment instead of `ptr::write` does not cause the old -/// // uninitialized value to be dropped. Also if there is a panic during -/// // this loop, we have a memory leak, but there is no memory safety -/// // issue. +/// // Dropping a `MaybeUninit` does nothing, so if there is a panic during this loop, +/// // we have a memory leak, but there is no memory safety issue. /// for elem in &mut data[..] { /// elem.write(vec![42]); /// } @@ -152,7 +146,6 @@ use crate::slice; /// /// ``` /// use std::mem::MaybeUninit; -/// use std::ptr; /// /// // Create an uninitialized array of `MaybeUninit`. The `assume_init` is /// // safe because the type we are claiming to have initialized here is a @@ -168,7 +161,7 @@ use crate::slice; /// /// // For each item in the array, drop if we allocated it. /// for elem in &mut data[0..data_len] { -/// unsafe { ptr::drop_in_place(elem.as_mut_ptr()); } +/// unsafe { elem.assume_init_drop(); } /// } /// ``` /// @@ -653,7 +646,7 @@ impl<T> MaybeUninit<T> { /// implements the [`Copy`] trait or not. When using multiple copies of the /// data (by calling `assume_init_read` multiple times, or first calling /// `assume_init_read` and then [`assume_init`]), it is your responsibility - /// to ensure that that data may indeed be duplicated. + /// to ensure that data may indeed be duplicated. /// /// [inv]: #initialization-invariant /// [`assume_init`]: MaybeUninit::assume_init @@ -1290,3 +1283,42 @@ impl<T> MaybeUninit<T> { } } } + +impl<T, const N: usize> MaybeUninit<[T; N]> { + /// Transposes a `MaybeUninit<[T; N]>` into a `[MaybeUninit<T>; N]`. + /// + /// # Examples + /// + /// ``` + /// #![feature(maybe_uninit_uninit_array_transpose)] + /// # use std::mem::MaybeUninit; + /// + /// let data: [MaybeUninit<u8>; 1000] = MaybeUninit::uninit().transpose(); + /// ``` + #[unstable(feature = "maybe_uninit_uninit_array_transpose", issue = "96097")] + #[inline] + pub const fn transpose(self) -> [MaybeUninit<T>; N] { + // SAFETY: T and MaybeUninit<T> have the same layout + unsafe { super::transmute_copy(&ManuallyDrop::new(self)) } + } +} + +impl<T, const N: usize> [MaybeUninit<T>; N] { + /// Transposes a `[MaybeUninit<T>; N]` into a `MaybeUninit<[T; N]>`. + /// + /// # Examples + /// + /// ``` + /// #![feature(maybe_uninit_uninit_array_transpose)] + /// # use std::mem::MaybeUninit; + /// + /// let data = [MaybeUninit::<u8>::uninit(); 1000]; + /// let data: MaybeUninit<[u8; 1000]> = data.transpose(); + /// ``` + #[unstable(feature = "maybe_uninit_uninit_array_transpose", issue = "96097")] + #[inline] + pub const fn transpose(self) -> MaybeUninit<[T; N]> { + // SAFETY: T and MaybeUninit<T> have the same layout + unsafe { super::transmute_copy(&ManuallyDrop::new(self)) } + } +} diff --git a/library/core/src/mem/mod.rs b/library/core/src/mem/mod.rs index 20b2d5e26..9195da5a4 100644 --- a/library/core/src/mem/mod.rs +++ b/library/core/src/mem/mod.rs @@ -21,11 +21,10 @@ mod maybe_uninit; #[stable(feature = "maybe_uninit", since = "1.36.0")] pub use maybe_uninit::MaybeUninit; -mod valid_align; -// For now this type is left crate-local. It could potentially make sense to expose -// it publicly, as it would be a nice parameter type for methods which need to take -// alignment as a parameter, such as `Layout::padding_needed_for`. -pub(crate) use valid_align::ValidAlign; +// FIXME: This is left here for now to avoid complications around pending reverts. +// Once <https://github.com/rust-lang/rust/issues/101899> is fully resolved, +// this should be removed and the references in `alloc::Layout` updated. +pub(crate) use ptr::Alignment as ValidAlign; mod transmutability; #[unstable(feature = "transmutability", issue = "99571")] @@ -665,14 +664,14 @@ pub unsafe fn zeroed<T>() -> T { /// correctly: it has the same effect as [`MaybeUninit::uninit().assume_init()`][uninit]. /// As the [`assume_init` documentation][assume_init] explains, /// [the Rust compiler assumes][inv] that values are properly initialized. -/// As a consequence, calling e.g. `mem::uninitialized::<bool>()` causes immediate -/// undefined behavior for returning a `bool` that is not definitely either `true` -/// or `false`. Worse, truly uninitialized memory like what gets returned here +/// +/// Truly uninitialized memory like what gets returned here /// is special in that the compiler knows that it does not have a fixed value. /// This makes it undefined behavior to have uninitialized data in a variable even /// if that variable has an integer type. -/// (Notice that the rules around uninitialized integers are not finalized yet, but -/// until they are, it is advisable to avoid them.) +/// +/// Therefore, it is immediate undefined behavior to call this function on nearly all types, +/// including integer types and arrays of integer types, and even if the result is unused. /// /// [uninit]: MaybeUninit::uninit /// [assume_init]: MaybeUninit::assume_init @@ -1009,18 +1008,18 @@ pub fn copy<T: Copy>(x: &T) -> T { *x } -/// Interprets `src` as having type `&U`, and then reads `src` without moving +/// Interprets `src` as having type `&Dst`, and then reads `src` without moving /// the contained value. /// -/// This function will unsafely assume the pointer `src` is valid for [`size_of::<U>`][size_of] -/// bytes by transmuting `&T` to `&U` and then reading the `&U` (except that this is done in a way -/// that is correct even when `&U` has stricter alignment requirements than `&T`). It will also -/// unsafely create a copy of the contained value instead of moving out of `src`. +/// This function will unsafely assume the pointer `src` is valid for [`size_of::<Dst>`][size_of] +/// bytes by transmuting `&Src` to `&Dst` and then reading the `&Dst` (except that this is done +/// in a way that is correct even when `&Dst` has stricter alignment requirements than `&Src`). +/// It will also unsafely create a copy of the contained value instead of moving out of `src`. /// -/// It is not a compile-time error if `T` and `U` have different sizes, but it -/// is highly encouraged to only invoke this function where `T` and `U` have the -/// same size. This function triggers [undefined behavior][ub] if `U` is larger than -/// `T`. +/// It is not a compile-time error if `Src` and `Dst` have different sizes, but it +/// is highly encouraged to only invoke this function where `Src` and `Dst` have the +/// same size. This function triggers [undefined behavior][ub] if `Dst` is larger than +/// `Src`. /// /// [ub]: ../../reference/behavior-considered-undefined.html /// @@ -1053,19 +1052,22 @@ pub fn copy<T: Copy>(x: &T) -> T { #[must_use] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_unstable(feature = "const_transmute_copy", issue = "83165")] -pub const unsafe fn transmute_copy<T, U>(src: &T) -> U { - assert!(size_of::<T>() >= size_of::<U>(), "cannot transmute_copy if U is larger than T"); +pub const unsafe fn transmute_copy<Src, Dst>(src: &Src) -> Dst { + assert!( + size_of::<Src>() >= size_of::<Dst>(), + "cannot transmute_copy if Dst is larger than Src" + ); - // If U has a higher alignment requirement, src might not be suitably aligned. - if align_of::<U>() > align_of::<T>() { + // If Dst has a higher alignment requirement, src might not be suitably aligned. + if align_of::<Dst>() > align_of::<Src>() { // SAFETY: `src` is a reference which is guaranteed to be valid for reads. // The caller must guarantee that the actual transmutation is safe. - unsafe { ptr::read_unaligned(src as *const T as *const U) } + unsafe { ptr::read_unaligned(src as *const Src as *const Dst) } } else { // SAFETY: `src` is a reference which is guaranteed to be valid for reads. - // We just checked that `src as *const U` was properly aligned. + // We just checked that `src as *const Dst` was properly aligned. // The caller must guarantee that the actual transmutation is safe. - unsafe { ptr::read(src as *const T as *const U) } + unsafe { ptr::read(src as *const Src as *const Dst) } } } @@ -1178,3 +1180,44 @@ pub const fn discriminant<T>(v: &T) -> Discriminant<T> { pub const fn variant_count<T>() -> usize { intrinsics::variant_count::<T>() } + +/// Provides associated constants for various useful properties of types, +/// to give them a canonical form in our code and make them easier to read. +/// +/// This is here only to simplify all the ZST checks we need in the library. +/// It's not on a stabilization track right now. +#[doc(hidden)] +#[unstable(feature = "sized_type_properties", issue = "none")] +pub trait SizedTypeProperties: Sized { + /// `true` if this type requires no storage. + /// `false` if its [size](size_of) is greater than zero. + /// + /// # Examples + /// + /// ``` + /// #![feature(sized_type_properties)] + /// use core::mem::SizedTypeProperties; + /// + /// fn do_something_with<T>() { + /// if T::IS_ZST { + /// // ... special approach ... + /// } else { + /// // ... the normal thing ... + /// } + /// } + /// + /// struct MyUnit; + /// assert!(MyUnit::IS_ZST); + /// + /// // For negative checks, consider using UFCS to emphasize the negation + /// assert!(!<i32>::IS_ZST); + /// // As it can sometimes hide in the type otherwise + /// assert!(!String::IS_ZST); + /// ``` + #[doc(hidden)] + #[unstable(feature = "sized_type_properties", issue = "none")] + const IS_ZST: bool = size_of::<Self>() == 0; +} +#[doc(hidden)] +#[unstable(feature = "sized_type_properties", issue = "none")] +impl<T> SizedTypeProperties for T {} diff --git a/library/core/src/mem/transmutability.rs b/library/core/src/mem/transmutability.rs index b59a5b89d..3b98efff2 100644 --- a/library/core/src/mem/transmutability.rs +++ b/library/core/src/mem/transmutability.rs @@ -4,25 +4,20 @@ /// any value of type `Self` are safely transmutable into a value of type `Dst`, in a given `Context`, /// notwithstanding whatever safety checks you have asked the compiler to [`Assume`] are satisfied. #[unstable(feature = "transmutability", issue = "99571")] -#[cfg_attr(not(bootstrap), lang = "transmute_trait")] +#[lang = "transmute_trait"] #[rustc_on_unimplemented( message = "`{Src}` cannot be safely transmuted into `{Self}` in the defining scope of `{Context}`.", label = "`{Src}` cannot be safely transmuted into `{Self}` in the defining scope of `{Context}`." )] -pub unsafe trait BikeshedIntrinsicFrom< - Src, - Context, - const ASSUME_ALIGNMENT: bool, - const ASSUME_LIFETIMES: bool, - const ASSUME_VALIDITY: bool, - const ASSUME_VISIBILITY: bool, -> where +pub unsafe trait BikeshedIntrinsicFrom<Src, Context, const ASSUME: Assume = { Assume::NOTHING }> +where Src: ?Sized, { } /// What transmutation safety conditions shall the compiler assume that *you* are checking? #[unstable(feature = "transmutability", issue = "99571")] +#[lang = "transmute_opts"] #[derive(PartialEq, Eq, Clone, Copy, Debug)] pub struct Assume { /// When `true`, the compiler assumes that *you* are ensuring (either dynamically or statically) that @@ -33,11 +28,80 @@ pub struct Assume { /// that violates Rust's memory model. pub lifetimes: bool, + /// When `true`, the compiler assumes that *you* have ensured that it is safe for you to violate the + /// type and field privacy of the destination type (and sometimes of the source type, too). + pub safety: bool, + /// When `true`, the compiler assumes that *you* are ensuring that the source type is actually a valid /// instance of the destination type. pub validity: bool, +} - /// When `true`, the compiler assumes that *you* have ensured that it is safe for you to violate the - /// type and field privacy of the destination type (and sometimes of the source type, too). - pub visibility: bool, +impl Assume { + /// Do not assume that *you* have ensured any safety properties are met. + #[unstable(feature = "transmutability", issue = "99571")] + pub const NOTHING: Self = + Self { alignment: false, lifetimes: false, safety: false, validity: false }; + + /// Assume only that alignment conditions are met. + #[unstable(feature = "transmutability", issue = "99571")] + pub const ALIGNMENT: Self = Self { alignment: true, ..Self::NOTHING }; + + /// Assume only that lifetime conditions are met. + #[unstable(feature = "transmutability", issue = "99571")] + pub const LIFETIMES: Self = Self { lifetimes: true, ..Self::NOTHING }; + + /// Assume only that safety conditions are met. + #[unstable(feature = "transmutability", issue = "99571")] + pub const SAFETY: Self = Self { safety: true, ..Self::NOTHING }; + + /// Assume only that dynamically-satisfiable validity conditions are met. + #[unstable(feature = "transmutability", issue = "99571")] + pub const VALIDITY: Self = Self { validity: true, ..Self::NOTHING }; + + /// Assume both `self` and `other_assumptions`. + #[unstable(feature = "transmutability", issue = "99571")] + pub const fn and(self, other_assumptions: Self) -> Self { + Self { + alignment: self.alignment || other_assumptions.alignment, + lifetimes: self.lifetimes || other_assumptions.lifetimes, + safety: self.safety || other_assumptions.safety, + validity: self.validity || other_assumptions.validity, + } + } + + /// Assume `self`, excepting `other_assumptions`. + #[unstable(feature = "transmutability", issue = "99571")] + pub const fn but_not(self, other_assumptions: Self) -> Self { + Self { + alignment: self.alignment && !other_assumptions.alignment, + lifetimes: self.lifetimes && !other_assumptions.lifetimes, + safety: self.safety && !other_assumptions.safety, + validity: self.validity && !other_assumptions.validity, + } + } +} + +// FIXME(jswrenn): This const op is not actually usable. Why? +// https://github.com/rust-lang/rust/pull/100726#issuecomment-1219928926 +#[unstable(feature = "transmutability", issue = "99571")] +#[rustc_const_unstable(feature = "transmutability", issue = "99571")] +impl const core::ops::Add for Assume { + type Output = Assume; + + fn add(self, other_assumptions: Assume) -> Assume { + self.and(other_assumptions) + } +} + +// FIXME(jswrenn): This const op is not actually usable. Why? +// https://github.com/rust-lang/rust/pull/100726#issuecomment-1219928926 +#[unstable(feature = "transmutability", issue = "99571")] +#[rustc_const_unstable(feature = "transmutability", issue = "99571")] +impl const core::ops::Sub for Assume { + type Output = Assume; + + fn sub(self, other_assumptions: Assume) -> Assume { + self.but_not(other_assumptions) + } } diff --git a/library/core/src/num/bignum.rs b/library/core/src/num/bignum.rs index de85fdd6e..d2a21b6b3 100644 --- a/library/core/src/num/bignum.rs +++ b/library/core/src/num/bignum.rs @@ -137,7 +137,7 @@ macro_rules! define_bignum { // Find the most significant non-zero digit. let msd = digits.iter().rposition(|&x| x != 0); match msd { - Some(msd) => msd * digitbits + digits[msd].log2() as usize + 1, + Some(msd) => msd * digitbits + digits[msd].ilog2() as usize + 1, // There are no non-zero digits, i.e., the number is zero. _ => 0, } diff --git a/library/core/src/num/dec2flt/decimal.rs b/library/core/src/num/dec2flt/decimal.rs index f8edc3625..2019f71e6 100644 --- a/library/core/src/num/dec2flt/decimal.rs +++ b/library/core/src/num/dec2flt/decimal.rs @@ -32,7 +32,7 @@ impl Default for Decimal { impl Decimal { /// The maximum number of digits required to unambiguously round a float. /// - /// For a double-precision IEEE-754 float, this required 767 digits, + /// For a double-precision IEEE 754 float, this required 767 digits, /// so we store the max digits + 1. /// /// We can exactly represent a float in radix `b` from radix 2 if diff --git a/library/core/src/num/dec2flt/lemire.rs b/library/core/src/num/dec2flt/lemire.rs index 75405f471..9f7594460 100644 --- a/library/core/src/num/dec2flt/lemire.rs +++ b/library/core/src/num/dec2flt/lemire.rs @@ -6,7 +6,7 @@ use crate::num::dec2flt::table::{ LARGEST_POWER_OF_FIVE, POWER_OF_FIVE_128, SMALLEST_POWER_OF_FIVE, }; -/// Compute a float using an extended-precision representation. +/// Compute w * 10^q using an extended-precision float representation. /// /// Fast conversion of a the significant digits and decimal exponent /// a float to an extended representation with a binary float. This @@ -76,7 +76,7 @@ pub fn compute_float<F: RawFloat>(q: i64, mut w: u64) -> BiasedFp { return BiasedFp { f: mantissa, e: power2 }; } // Need to handle rounding ties. Normally, we need to round up, - // but if we fall right in between and and we have an even basis, we + // but if we fall right in between and we have an even basis, we // need to round down. // // This will only occur if: diff --git a/library/core/src/num/error.rs b/library/core/src/num/error.rs index 1a223016d..768dd8781 100644 --- a/library/core/src/num/error.rs +++ b/library/core/src/num/error.rs @@ -1,6 +1,7 @@ //! Error types for conversion to integral types. use crate::convert::Infallible; +use crate::error::Error; use crate::fmt; /// The error type returned when a checked integral type conversion fails. @@ -144,3 +145,19 @@ impl fmt::Display for ParseIntError { self.__description().fmt(f) } } + +#[stable(feature = "rust1", since = "1.0.0")] +impl Error for ParseIntError { + #[allow(deprecated)] + fn description(&self) -> &str { + self.__description() + } +} + +#[stable(feature = "try_from", since = "1.34.0")] +impl Error for TryFromIntError { + #[allow(deprecated)] + fn description(&self) -> &str { + self.__description() + } +} diff --git a/library/core/src/num/f32.rs b/library/core/src/num/f32.rs index 6548ad2e5..2c6a0ba64 100644 --- a/library/core/src/num/f32.rs +++ b/library/core/src/num/f32.rs @@ -1,4 +1,4 @@ -//! Constants specific to the `f32` single-precision floating point type. +//! Constants for the `f32` single-precision floating point type. //! //! *[See also the `f32` primitive type][f32].* //! @@ -394,7 +394,7 @@ impl f32 { /// Not a Number (NaN). /// - /// Note that IEEE-745 doesn't define just a single NaN value; + /// Note that IEEE 754 doesn't define just a single NaN value; /// a plethora of bit patterns are considered to be NaN. /// Furthermore, the standard makes a difference /// between a "signaling" and a "quiet" NaN, @@ -632,7 +632,7 @@ impl f32 { } /// Returns `true` if `self` has a positive sign, including `+0.0`, NaNs with - /// positive sign bit and positive infinity. Note that IEEE-745 doesn't assign any + /// positive sign bit and positive infinity. Note that IEEE 754 doesn't assign any /// meaning to the sign bit in case of a NaN, and as Rust doesn't guarantee that /// the bit pattern of NaNs are conserved over arithmetic operations, the result of /// `is_sign_positive` on a NaN might produce an unexpected result in some cases. @@ -654,7 +654,7 @@ impl f32 { } /// Returns `true` if `self` has a negative sign, including `-0.0`, NaNs with - /// negative sign bit and negative infinity. Note that IEEE-745 doesn't assign any + /// negative sign bit and negative infinity. Note that IEEE 754 doesn't assign any /// meaning to the sign bit in case of a NaN, and as Rust doesn't guarantee that /// the bit pattern of NaNs are conserved over arithmetic operations, the result of /// `is_sign_negative` on a NaN might produce an unexpected result in some cases. @@ -678,6 +678,106 @@ impl f32 { unsafe { mem::transmute::<f32, u32>(self) & 0x8000_0000 != 0 } } + /// Returns the least number greater than `self`. + /// + /// Let `TINY` be the smallest representable positive `f32`. Then, + /// - if `self.is_nan()`, this returns `self`; + /// - if `self` is [`NEG_INFINITY`], this returns [`MIN`]; + /// - if `self` is `-TINY`, this returns -0.0; + /// - if `self` is -0.0 or +0.0, this returns `TINY`; + /// - if `self` is [`MAX`] or [`INFINITY`], this returns [`INFINITY`]; + /// - otherwise the unique least value greater than `self` is returned. + /// + /// The identity `x.next_up() == -(-x).next_down()` holds for all non-NaN `x`. When `x` + /// is finite `x == x.next_up().next_down()` also holds. + /// + /// ```rust + /// #![feature(float_next_up_down)] + /// // f32::EPSILON is the difference between 1.0 and the next number up. + /// assert_eq!(1.0f32.next_up(), 1.0 + f32::EPSILON); + /// // But not for most numbers. + /// assert!(0.1f32.next_up() < 0.1 + f32::EPSILON); + /// assert_eq!(16777216f32.next_up(), 16777218.0); + /// ``` + /// + /// [`NEG_INFINITY`]: Self::NEG_INFINITY + /// [`INFINITY`]: Self::INFINITY + /// [`MIN`]: Self::MIN + /// [`MAX`]: Self::MAX + #[unstable(feature = "float_next_up_down", issue = "91399")] + #[rustc_const_unstable(feature = "float_next_up_down", issue = "91399")] + pub const fn next_up(self) -> Self { + // We must use strictly integer arithmetic to prevent denormals from + // flushing to zero after an arithmetic operation on some platforms. + const TINY_BITS: u32 = 0x1; // Smallest positive f32. + const CLEAR_SIGN_MASK: u32 = 0x7fff_ffff; + + let bits = self.to_bits(); + if self.is_nan() || bits == Self::INFINITY.to_bits() { + return self; + } + + let abs = bits & CLEAR_SIGN_MASK; + let next_bits = if abs == 0 { + TINY_BITS + } else if bits == abs { + bits + 1 + } else { + bits - 1 + }; + Self::from_bits(next_bits) + } + + /// Returns the greatest number less than `self`. + /// + /// Let `TINY` be the smallest representable positive `f32`. Then, + /// - if `self.is_nan()`, this returns `self`; + /// - if `self` is [`INFINITY`], this returns [`MAX`]; + /// - if `self` is `TINY`, this returns 0.0; + /// - if `self` is -0.0 or +0.0, this returns `-TINY`; + /// - if `self` is [`MIN`] or [`NEG_INFINITY`], this returns [`NEG_INFINITY`]; + /// - otherwise the unique greatest value less than `self` is returned. + /// + /// The identity `x.next_down() == -(-x).next_up()` holds for all non-NaN `x`. When `x` + /// is finite `x == x.next_down().next_up()` also holds. + /// + /// ```rust + /// #![feature(float_next_up_down)] + /// let x = 1.0f32; + /// // Clamp value into range [0, 1). + /// let clamped = x.clamp(0.0, 1.0f32.next_down()); + /// assert!(clamped < 1.0); + /// assert_eq!(clamped.next_up(), 1.0); + /// ``` + /// + /// [`NEG_INFINITY`]: Self::NEG_INFINITY + /// [`INFINITY`]: Self::INFINITY + /// [`MIN`]: Self::MIN + /// [`MAX`]: Self::MAX + #[unstable(feature = "float_next_up_down", issue = "91399")] + #[rustc_const_unstable(feature = "float_next_up_down", issue = "91399")] + pub const fn next_down(self) -> Self { + // We must use strictly integer arithmetic to prevent denormals from + // flushing to zero after an arithmetic operation on some platforms. + const NEG_TINY_BITS: u32 = 0x8000_0001; // Smallest (in magnitude) negative f32. + const CLEAR_SIGN_MASK: u32 = 0x7fff_ffff; + + let bits = self.to_bits(); + if self.is_nan() || bits == Self::NEG_INFINITY.to_bits() { + return self; + } + + let abs = bits & CLEAR_SIGN_MASK; + let next_bits = if abs == 0 { + NEG_TINY_BITS + } else if bits == abs { + bits - 1 + } else { + bits + 1 + }; + Self::from_bits(next_bits) + } + /// Takes the reciprocal (inverse) of a number, `1/x`. /// /// ``` @@ -733,7 +833,7 @@ impl f32 { /// Returns the maximum of the two numbers, ignoring NaN. /// /// If one of the arguments is NaN, then the other argument is returned. - /// This follows the IEEE-754 2008 semantics for maxNum, except for handling of signaling NaNs; + /// This follows the IEEE 754-2008 semantics for maxNum, except for handling of signaling NaNs; /// this function handles all NaNs the same way and avoids maxNum's problems with associativity. /// This also matches the behavior of libm’s fmax. /// @@ -753,7 +853,7 @@ impl f32 { /// Returns the minimum of the two numbers, ignoring NaN. /// /// If one of the arguments is NaN, then the other argument is returned. - /// This follows the IEEE-754 2008 semantics for minNum, except for handling of signaling NaNs; + /// This follows the IEEE 754-2008 semantics for minNum, except for handling of signaling NaNs; /// this function handles all NaNs the same way and avoids minNum's problems with associativity. /// This also matches the behavior of libm’s fmin. /// @@ -933,10 +1033,14 @@ impl f32 { } } } - // SAFETY: `u32` is a plain old datatype so we can always... uh... - // ...look, just pretend you forgot what you just read. - // Stability concerns. - let rt_f32_to_u32 = |rt| unsafe { mem::transmute::<f32, u32>(rt) }; + + #[inline(always)] // See https://github.com/rust-lang/compiler-builtins/issues/491 + fn rt_f32_to_u32(x: f32) -> u32 { + // SAFETY: `u32` is a plain old datatype so we can always... uh... + // ...look, just pretend you forgot what you just read. + // Stability concerns. + unsafe { mem::transmute(x) } + } // SAFETY: We use internal implementations that either always work or fail at compile time. unsafe { intrinsics::const_eval_select((self,), ct_f32_to_u32, rt_f32_to_u32) } } @@ -947,9 +1051,9 @@ impl f32 { /// It turns out this is incredibly portable, for two reasons: /// /// * Floats and Ints have the same endianness on all supported platforms. - /// * IEEE-754 very precisely specifies the bit layout of floats. + /// * IEEE 754 very precisely specifies the bit layout of floats. /// - /// However there is one caveat: prior to the 2008 version of IEEE-754, how + /// However there is one caveat: prior to the 2008 version of IEEE 754, how /// to interpret the NaN signaling bit wasn't actually specified. Most platforms /// (notably x86 and ARM) picked the interpretation that was ultimately /// standardized in 2008, but some didn't (notably MIPS). As a result, all @@ -1021,10 +1125,14 @@ impl f32 { } } } - // SAFETY: `u32` is a plain old datatype so we can always... uh... - // ...look, just pretend you forgot what you just read. - // Stability concerns. - let rt_u32_to_f32 = |rt| unsafe { mem::transmute::<u32, f32>(rt) }; + + #[inline(always)] // See https://github.com/rust-lang/compiler-builtins/issues/491 + fn rt_u32_to_f32(x: u32) -> f32 { + // SAFETY: `u32` is a plain old datatype so we can always... uh... + // ...look, just pretend you forgot what you just read. + // Stability concerns. + unsafe { mem::transmute(x) } + } // SAFETY: We use internal implementations that either always work or fail at compile time. unsafe { intrinsics::const_eval_select((v,), ct_u32_to_f32, rt_u32_to_f32) } } @@ -1282,15 +1390,14 @@ impl f32 { #[must_use = "method returns a new number and does not mutate the original value"] #[stable(feature = "clamp", since = "1.50.0")] #[inline] - pub fn clamp(self, min: f32, max: f32) -> f32 { + pub fn clamp(mut self, min: f32, max: f32) -> f32 { assert!(min <= max); - let mut x = self; - if x < min { - x = min; + if self < min { + self = min; } - if x > max { - x = max; + if self > max { + self = max; } - x + self } } diff --git a/library/core/src/num/f64.rs b/library/core/src/num/f64.rs index 75c92c2f8..fd3c18ce2 100644 --- a/library/core/src/num/f64.rs +++ b/library/core/src/num/f64.rs @@ -1,4 +1,4 @@ -//! Constants specific to the `f64` double-precision floating point type. +//! Constants for the `f64` double-precision floating point type. //! //! *[See also the `f64` primitive type][f64].* //! @@ -393,7 +393,7 @@ impl f64 { /// Not a Number (NaN). /// - /// Note that IEEE-745 doesn't define just a single NaN value; + /// Note that IEEE 754 doesn't define just a single NaN value; /// a plethora of bit patterns are considered to be NaN. /// Furthermore, the standard makes a difference /// between a "signaling" and a "quiet" NaN, @@ -624,7 +624,7 @@ impl f64 { } /// Returns `true` if `self` has a positive sign, including `+0.0`, NaNs with - /// positive sign bit and positive infinity. Note that IEEE-745 doesn't assign any + /// positive sign bit and positive infinity. Note that IEEE 754 doesn't assign any /// meaning to the sign bit in case of a NaN, and as Rust doesn't guarantee that /// the bit pattern of NaNs are conserved over arithmetic operations, the result of /// `is_sign_positive` on a NaN might produce an unexpected result in some cases. @@ -655,7 +655,7 @@ impl f64 { } /// Returns `true` if `self` has a negative sign, including `-0.0`, NaNs with - /// negative sign bit and negative infinity. Note that IEEE-745 doesn't assign any + /// negative sign bit and negative infinity. Note that IEEE 754 doesn't assign any /// meaning to the sign bit in case of a NaN, and as Rust doesn't guarantee that /// the bit pattern of NaNs are conserved over arithmetic operations, the result of /// `is_sign_negative` on a NaN might produce an unexpected result in some cases. @@ -688,6 +688,106 @@ impl f64 { self.is_sign_negative() } + /// Returns the least number greater than `self`. + /// + /// Let `TINY` be the smallest representable positive `f64`. Then, + /// - if `self.is_nan()`, this returns `self`; + /// - if `self` is [`NEG_INFINITY`], this returns [`MIN`]; + /// - if `self` is `-TINY`, this returns -0.0; + /// - if `self` is -0.0 or +0.0, this returns `TINY`; + /// - if `self` is [`MAX`] or [`INFINITY`], this returns [`INFINITY`]; + /// - otherwise the unique least value greater than `self` is returned. + /// + /// The identity `x.next_up() == -(-x).next_down()` holds for all non-NaN `x`. When `x` + /// is finite `x == x.next_up().next_down()` also holds. + /// + /// ```rust + /// #![feature(float_next_up_down)] + /// // f64::EPSILON is the difference between 1.0 and the next number up. + /// assert_eq!(1.0f64.next_up(), 1.0 + f64::EPSILON); + /// // But not for most numbers. + /// assert!(0.1f64.next_up() < 0.1 + f64::EPSILON); + /// assert_eq!(9007199254740992f64.next_up(), 9007199254740994.0); + /// ``` + /// + /// [`NEG_INFINITY`]: Self::NEG_INFINITY + /// [`INFINITY`]: Self::INFINITY + /// [`MIN`]: Self::MIN + /// [`MAX`]: Self::MAX + #[unstable(feature = "float_next_up_down", issue = "91399")] + #[rustc_const_unstable(feature = "float_next_up_down", issue = "91399")] + pub const fn next_up(self) -> Self { + // We must use strictly integer arithmetic to prevent denormals from + // flushing to zero after an arithmetic operation on some platforms. + const TINY_BITS: u64 = 0x1; // Smallest positive f64. + const CLEAR_SIGN_MASK: u64 = 0x7fff_ffff_ffff_ffff; + + let bits = self.to_bits(); + if self.is_nan() || bits == Self::INFINITY.to_bits() { + return self; + } + + let abs = bits & CLEAR_SIGN_MASK; + let next_bits = if abs == 0 { + TINY_BITS + } else if bits == abs { + bits + 1 + } else { + bits - 1 + }; + Self::from_bits(next_bits) + } + + /// Returns the greatest number less than `self`. + /// + /// Let `TINY` be the smallest representable positive `f64`. Then, + /// - if `self.is_nan()`, this returns `self`; + /// - if `self` is [`INFINITY`], this returns [`MAX`]; + /// - if `self` is `TINY`, this returns 0.0; + /// - if `self` is -0.0 or +0.0, this returns `-TINY`; + /// - if `self` is [`MIN`] or [`NEG_INFINITY`], this returns [`NEG_INFINITY`]; + /// - otherwise the unique greatest value less than `self` is returned. + /// + /// The identity `x.next_down() == -(-x).next_up()` holds for all non-NaN `x`. When `x` + /// is finite `x == x.next_down().next_up()` also holds. + /// + /// ```rust + /// #![feature(float_next_up_down)] + /// let x = 1.0f64; + /// // Clamp value into range [0, 1). + /// let clamped = x.clamp(0.0, 1.0f64.next_down()); + /// assert!(clamped < 1.0); + /// assert_eq!(clamped.next_up(), 1.0); + /// ``` + /// + /// [`NEG_INFINITY`]: Self::NEG_INFINITY + /// [`INFINITY`]: Self::INFINITY + /// [`MIN`]: Self::MIN + /// [`MAX`]: Self::MAX + #[unstable(feature = "float_next_up_down", issue = "91399")] + #[rustc_const_unstable(feature = "float_next_up_down", issue = "91399")] + pub const fn next_down(self) -> Self { + // We must use strictly integer arithmetic to prevent denormals from + // flushing to zero after an arithmetic operation on some platforms. + const NEG_TINY_BITS: u64 = 0x8000_0000_0000_0001; // Smallest (in magnitude) negative f64. + const CLEAR_SIGN_MASK: u64 = 0x7fff_ffff_ffff_ffff; + + let bits = self.to_bits(); + if self.is_nan() || bits == Self::NEG_INFINITY.to_bits() { + return self; + } + + let abs = bits & CLEAR_SIGN_MASK; + let next_bits = if abs == 0 { + NEG_TINY_BITS + } else if bits == abs { + bits - 1 + } else { + bits + 1 + }; + Self::from_bits(next_bits) + } + /// Takes the reciprocal (inverse) of a number, `1/x`. /// /// ``` @@ -744,7 +844,7 @@ impl f64 { /// Returns the maximum of the two numbers, ignoring NaN. /// /// If one of the arguments is NaN, then the other argument is returned. - /// This follows the IEEE-754 2008 semantics for maxNum, except for handling of signaling NaNs; + /// This follows the IEEE 754-2008 semantics for maxNum, except for handling of signaling NaNs; /// this function handles all NaNs the same way and avoids maxNum's problems with associativity. /// This also matches the behavior of libm’s fmax. /// @@ -764,7 +864,7 @@ impl f64 { /// Returns the minimum of the two numbers, ignoring NaN. /// /// If one of the arguments is NaN, then the other argument is returned. - /// This follows the IEEE-754 2008 semantics for minNum, except for handling of signaling NaNs; + /// This follows the IEEE 754-2008 semantics for minNum, except for handling of signaling NaNs; /// this function handles all NaNs the same way and avoids minNum's problems with associativity. /// This also matches the behavior of libm’s fmin. /// @@ -926,10 +1026,14 @@ impl f64 { } } } - // SAFETY: `u64` is a plain old datatype so we can always... uh... - // ...look, just pretend you forgot what you just read. - // Stability concerns. - let rt_f64_to_u64 = |rt| unsafe { mem::transmute::<f64, u64>(rt) }; + + #[inline(always)] // See https://github.com/rust-lang/compiler-builtins/issues/491 + fn rt_f64_to_u64(rt: f64) -> u64 { + // SAFETY: `u64` is a plain old datatype so we can always... uh... + // ...look, just pretend you forgot what you just read. + // Stability concerns. + unsafe { mem::transmute::<f64, u64>(rt) } + } // SAFETY: We use internal implementations that either always work or fail at compile time. unsafe { intrinsics::const_eval_select((self,), ct_f64_to_u64, rt_f64_to_u64) } } @@ -940,9 +1044,9 @@ impl f64 { /// It turns out this is incredibly portable, for two reasons: /// /// * Floats and Ints have the same endianness on all supported platforms. - /// * IEEE-754 very precisely specifies the bit layout of floats. + /// * IEEE 754 very precisely specifies the bit layout of floats. /// - /// However there is one caveat: prior to the 2008 version of IEEE-754, how + /// However there is one caveat: prior to the 2008 version of IEEE 754, how /// to interpret the NaN signaling bit wasn't actually specified. Most platforms /// (notably x86 and ARM) picked the interpretation that was ultimately /// standardized in 2008, but some didn't (notably MIPS). As a result, all @@ -1019,10 +1123,14 @@ impl f64 { } } } - // SAFETY: `u64` is a plain old datatype so we can always... uh... - // ...look, just pretend you forgot what you just read. - // Stability concerns. - let rt_u64_to_f64 = |rt| unsafe { mem::transmute::<u64, f64>(rt) }; + + #[inline(always)] // See https://github.com/rust-lang/compiler-builtins/issues/491 + fn rt_u64_to_f64(rt: u64) -> f64 { + // SAFETY: `u64` is a plain old datatype so we can always... uh... + // ...look, just pretend you forgot what you just read. + // Stability concerns. + unsafe { mem::transmute::<u64, f64>(rt) } + } // SAFETY: We use internal implementations that either always work or fail at compile time. unsafe { intrinsics::const_eval_select((v,), ct_u64_to_f64, rt_u64_to_f64) } } @@ -1280,15 +1388,14 @@ impl f64 { #[must_use = "method returns a new number and does not mutate the original value"] #[stable(feature = "clamp", since = "1.50.0")] #[inline] - pub fn clamp(self, min: f64, max: f64) -> f64 { + pub fn clamp(mut self, min: f64, max: f64) -> f64 { assert!(min <= max); - let mut x = self; - if x < min { - x = min; + if self < min { + self = min; } - if x > max { - x = max; + if self > max { + self = max; } - x + self } } diff --git a/library/core/src/num/flt2dec/strategy/grisu.rs b/library/core/src/num/flt2dec/strategy/grisu.rs index a4cb51c62..ed3e0edaf 100644 --- a/library/core/src/num/flt2dec/strategy/grisu.rs +++ b/library/core/src/num/flt2dec/strategy/grisu.rs @@ -253,7 +253,6 @@ pub fn format_shortest_opt<'a>( let delta1frac = delta1 & ((1 << e) - 1); // render integral parts, while checking for the accuracy at each step. - let mut kappa = max_kappa as i16; let mut ten_kappa = max_ten_kappa; // 10^kappa let mut remainder = plus1int; // digits yet to be rendered loop { @@ -290,12 +289,10 @@ pub fn format_shortest_opt<'a>( // the exact number of digits is `max_kappa + 1` as `plus1 < 10^(max_kappa+1)`. if i > max_kappa as usize { debug_assert_eq!(ten_kappa, 1); - debug_assert_eq!(kappa, 0); break; } // restore invariants - kappa -= 1; ten_kappa /= 10; remainder = r; } @@ -338,7 +335,6 @@ pub fn format_shortest_opt<'a>( } // restore invariants - kappa -= 1; remainder = r; } diff --git a/library/core/src/num/int_log10.rs b/library/core/src/num/int_log10.rs index cc26c04a5..80472528f 100644 --- a/library/core/src/num/int_log10.rs +++ b/library/core/src/num/int_log10.rs @@ -1,5 +1,5 @@ /// These functions compute the integer logarithm of their type, assuming -/// that someone has already checked that the the value is strictly positive. +/// that someone has already checked that the value is strictly positive. // 0 < val <= u8::MAX #[inline] diff --git a/library/core/src/num/int_macros.rs b/library/core/src/num/int_macros.rs index a66de19ba..914dca61b 100644 --- a/library/core/src/num/int_macros.rs +++ b/library/core/src/num/int_macros.rs @@ -464,12 +464,11 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_unsigned(2), Some(3));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add_unsigned(3), None);")] /// ``` - #[unstable(feature = "mixed_integer_ops", issue = "87840")] - #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[stable(feature = "mixed_integer_ops", since = "1.66.0")] + #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -533,12 +532,11 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_unsigned(2), Some(-1));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub_unsigned(3), None);")] /// ``` - #[unstable(feature = "mixed_integer_ops", issue = "87840")] - #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[stable(feature = "mixed_integer_ops", since = "1.66.0")] + #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -654,7 +652,6 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(2), Some(1));")] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(0), None);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem(-1), None);")] @@ -706,7 +703,6 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_neg(), Some(-5));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_neg(), None);")] /// ``` @@ -822,7 +818,6 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// #[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").checked_abs(), Some(5));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_abs(), None);")] /// ``` @@ -874,7 +869,7 @@ macro_rules! int_impl { // Deal with the final bit of the exponent separately, since // squaring the base afterwards is not necessary and may cause a // needless overflow. - Some(try_opt!(acc.checked_mul(base))) + acc.checked_mul(base) } /// Saturating integer addition. Computes `self + rhs`, saturating at the numeric @@ -907,12 +902,11 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_unsigned(2), 3);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add_unsigned(100), ", stringify!($SelfT), "::MAX);")] /// ``` - #[unstable(feature = "mixed_integer_ops", issue = "87840")] - #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[stable(feature = "mixed_integer_ops", since = "1.66.0")] + #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -954,12 +948,11 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub_unsigned(127), -27);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub_unsigned(100), ", stringify!($SelfT), "::MIN);")] /// ``` - #[unstable(feature = "mixed_integer_ops", issue = "87840")] - #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[stable(feature = "mixed_integer_ops", since = "1.66.0")] + #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -1030,7 +1023,6 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".saturating_mul(12), 120);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_mul(10), ", stringify!($SelfT), "::MAX);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_mul(10), ", stringify!($SelfT), "::MIN);")] @@ -1089,7 +1081,6 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// #[doc = concat!("assert_eq!((-4", stringify!($SelfT), ").saturating_pow(3), -64);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(2), ", stringify!($SelfT), "::MAX);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(3), ", stringify!($SelfT), "::MIN);")] @@ -1135,12 +1126,11 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add_unsigned(27), 127);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add_unsigned(2), ", stringify!($SelfT), "::MIN + 1);")] /// ``` - #[unstable(feature = "mixed_integer_ops", issue = "87840")] - #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[stable(feature = "mixed_integer_ops", since = "1.66.0")] + #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] @@ -1176,12 +1166,11 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub_unsigned(127), -127);")] #[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub_unsigned(", stringify!($UnsignedT), "::MAX), -1);")] /// ``` - #[unstable(feature = "mixed_integer_ops", issue = "87840")] - #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[stable(feature = "mixed_integer_ops", since = "1.66.0")] + #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] @@ -1504,7 +1493,6 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (", stringify!($SelfT), "::MIN, true));")] /// ``` @@ -1518,6 +1506,51 @@ macro_rules! int_impl { (a as Self, b) } + /// Calculates `self + rhs + carry` without the ability to overflow. + /// + /// Performs "signed ternary addition" which takes in an extra bit to add, and may return an + /// additional bit of overflow. This signed function is used only on the highest-ordered data, + /// for which the signed overflow result indicates whether the big integer overflowed or not. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(bigint_helper_methods)] + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".carrying_add(2, false), (7, false));")] + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".carrying_add(2, true), (8, false));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, false), (", stringify!($SelfT), "::MIN, true));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(0, true), (", stringify!($SelfT), "::MIN, true));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, true), (", stringify!($SelfT), "::MIN + 1, true));")] + #[doc = concat!("assert_eq!(", + stringify!($SelfT), "::MAX.carrying_add(", stringify!($SelfT), "::MAX, true), ", + "(-1, true));" + )] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.carrying_add(-1, true), (", stringify!($SelfT), "::MIN, false));")] + #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".carrying_add(", stringify!($SelfT), "::MAX, true), (", stringify!($SelfT), "::MIN, true));")] + /// ``` + /// + /// If `carry` is false, this method is equivalent to [`overflowing_add`](Self::overflowing_add): + /// + /// ``` + /// #![feature(bigint_helper_methods)] + #[doc = concat!("assert_eq!(5_", stringify!($SelfT), ".carrying_add(2, false), 5_", stringify!($SelfT), ".overflowing_add(2));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, false), ", stringify!($SelfT), "::MAX.overflowing_add(1));")] + /// ``` + #[unstable(feature = "bigint_helper_methods", issue = "85532")] + #[rustc_const_unstable(feature = "const_bigint_helper_methods", issue = "85532")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn carrying_add(self, rhs: Self, carry: bool) -> (Self, bool) { + // note: longer-term this should be done via an intrinsic. + // note: no intermediate overflow is required (https://github.com/rust-lang/rust/issues/85532#issuecomment-1032214946). + let (a, b) = self.overflowing_add(rhs); + let (c, d) = a.overflowing_add(carry as $SelfT); + (c, b != d) + } + /// Calculates `self` + `rhs` with an unsigned `rhs` /// /// Returns a tuple of the addition along with a boolean indicating @@ -1529,13 +1562,12 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_unsigned(2), (3, false));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_add_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MAX, false));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_add_unsigned(3), (", stringify!($SelfT), "::MIN, true));")] /// ``` - #[unstable(feature = "mixed_integer_ops", issue = "87840")] - #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[stable(feature = "mixed_integer_ops", since = "1.66.0")] + #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -1555,7 +1587,6 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_sub(1), (", stringify!($SelfT), "::MAX, true));")] /// ``` @@ -1569,6 +1600,39 @@ macro_rules! int_impl { (a as Self, b) } + /// Calculates `self - rhs - borrow` without the ability to overflow. + /// + /// Performs "signed ternary subtraction" which takes in an extra bit to subtract, and may return an + /// additional bit of overflow. This signed function is used only on the highest-ordered data, + /// for which the signed overflow result indicates whether the big integer overflowed or not. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(bigint_helper_methods)] + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".borrowing_sub(2, false), (3, false));")] + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".borrowing_sub(2, true), (2, false));")] + #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".borrowing_sub(1, false), (-1, false));")] + #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".borrowing_sub(1, true), (-2, false));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.borrowing_sub(1, true), (", stringify!($SelfT), "::MAX - 1, true));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.borrowing_sub(-1, false), (", stringify!($SelfT), "::MIN, true));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.borrowing_sub(-1, true), (", stringify!($SelfT), "::MAX, false));")] + /// ``` + #[unstable(feature = "bigint_helper_methods", issue = "85532")] + #[rustc_const_unstable(feature = "const_bigint_helper_methods", issue = "85532")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn borrowing_sub(self, rhs: Self, borrow: bool) -> (Self, bool) { + // note: longer-term this should be done via an intrinsic. + // note: no intermediate overflow is required (https://github.com/rust-lang/rust/issues/85532#issuecomment-1032214946). + let (a, b) = self.overflowing_sub(rhs); + let (c, d) = a.overflowing_sub(borrow as $SelfT); + (c, b != d) + } + /// Calculates `self` - `rhs` with an unsigned `rhs` /// /// Returns a tuple of the subtraction along with a boolean indicating @@ -1580,13 +1644,12 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_unsigned(2), (-1, false));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX).overflowing_sub_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MIN, false));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).overflowing_sub_unsigned(3), (", stringify!($SelfT), "::MAX, true));")] /// ``` - #[unstable(feature = "mixed_integer_ops", issue = "87840")] - #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[stable(feature = "mixed_integer_ops", since = "1.66.0")] + #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -1633,7 +1696,6 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div(-1), (", stringify!($SelfT), "::MIN, true));")] /// ``` @@ -1696,7 +1758,6 @@ macro_rules! int_impl { /// Basic usage: /// /// ``` - /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem(2), (1, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem(-1), (0, true));")] /// ``` @@ -2204,105 +2265,70 @@ macro_rules! int_impl { /// rounded down. /// /// This method might not be optimized owing to implementation details; - /// `log2` can produce results more efficiently for base 2, and `log10` + /// `ilog2` can produce results more efficiently for base 2, and `ilog10` /// can produce results more efficiently for base 10. /// /// # Panics /// - /// When the number is negative, zero, or if the base is not at least 2; it - /// panics in debug mode and the return value is 0 in release - /// mode. + /// This function will panic if `self` is less than or equal to zero, + /// or if `base` is less then 2. /// /// # Examples /// /// ``` /// #![feature(int_log)] - #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".log(5), 1);")] + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".ilog(5), 1);")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] - #[rustc_inherit_overflow_checks] - #[allow(arithmetic_overflow)] - pub const fn log(self, base: Self) -> u32 { - match self.checked_log(base) { - Some(n) => n, - None => { - // In debug builds, trigger a panic on None. - // This should optimize completely out in release builds. - let _ = Self::MAX + 1; - - 0 - }, - } + pub const fn ilog(self, base: Self) -> u32 { + assert!(base >= 2, "base of integer logarithm must be at least 2"); + self.checked_ilog(base).expect("argument of integer logarithm must be positive") } /// Returns the base 2 logarithm of the number, rounded down. /// /// # Panics /// - /// When the number is negative or zero it panics in debug mode and the return value - /// is 0 in release mode. + /// This function will panic if `self` is less than or equal to zero. /// /// # Examples /// /// ``` /// #![feature(int_log)] - #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".log2(), 1);")] + #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".ilog2(), 1);")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] - #[rustc_inherit_overflow_checks] - #[allow(arithmetic_overflow)] - pub const fn log2(self) -> u32 { - match self.checked_log2() { - Some(n) => n, - None => { - // In debug builds, trigger a panic on None. - // This should optimize completely out in release builds. - let _ = Self::MAX + 1; - - 0 - }, - } + pub const fn ilog2(self) -> u32 { + self.checked_ilog2().expect("argument of integer logarithm must be positive") } /// Returns the base 10 logarithm of the number, rounded down. /// /// # Panics /// - /// When the number is negative or zero it panics in debug mode and the return value - /// is 0 in release mode. + /// This function will panic if `self` is less than or equal to zero. /// /// # Example /// /// ``` /// #![feature(int_log)] - #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".log10(), 1);")] + #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".ilog10(), 1);")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] - #[rustc_inherit_overflow_checks] - #[allow(arithmetic_overflow)] - pub const fn log10(self) -> u32 { - match self.checked_log10() { - Some(n) => n, - None => { - // In debug builds, trigger a panic on None. - // This should optimize completely out in release builds. - let _ = Self::MAX + 1; - - 0 - }, - } + pub const fn ilog10(self) -> u32 { + self.checked_ilog10().expect("argument of integer logarithm must be positive") } /// Returns the logarithm of the number with respect to an arbitrary base, @@ -2311,20 +2337,20 @@ macro_rules! int_impl { /// Returns `None` if the number is negative or zero, or if the base is not at least 2. /// /// This method might not be optimized owing to implementation details; - /// `checked_log2` can produce results more efficiently for base 2, and - /// `checked_log10` can produce results more efficiently for base 10. + /// `checked_ilog2` can produce results more efficiently for base 2, and + /// `checked_ilog10` can produce results more efficiently for base 10. /// /// # Examples /// /// ``` /// #![feature(int_log)] - #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_log(5), Some(1));")] + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(5), Some(1));")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] - pub const fn checked_log(self, base: Self) -> Option<u32> { + pub const fn checked_ilog(self, base: Self) -> Option<u32> { if self <= 0 || base <= 1 { None } else { @@ -2333,7 +2359,7 @@ macro_rules! int_impl { // Optimization for 128 bit wide integers. if Self::BITS == 128 { - let b = Self::log2(self) / (Self::log2(base) + 1); + let b = Self::ilog2(self) / (Self::ilog2(base) + 1); n += b; r /= base.pow(b as u32); } @@ -2354,13 +2380,13 @@ macro_rules! int_impl { /// /// ``` /// #![feature(int_log)] - #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_log2(), Some(1));")] + #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_ilog2(), Some(1));")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] - pub const fn checked_log2(self) -> Option<u32> { + pub const fn checked_ilog2(self) -> Option<u32> { if self <= 0 { None } else { @@ -2378,13 +2404,13 @@ macro_rules! int_impl { /// /// ``` /// #![feature(int_log)] - #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_log10(), Some(1));")] + #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_ilog10(), Some(1));")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] - pub const fn checked_log10(self) -> Option<u32> { + pub const fn checked_ilog10(self) -> Option<u32> { if self > 0 { Some(int_log10::$ActualT(self as $ActualT)) } else { diff --git a/library/core/src/num/mod.rs b/library/core/src/num/mod.rs index f481399fd..311c5fa5b 100644 --- a/library/core/src/num/mod.rs +++ b/library/core/src/num/mod.rs @@ -3,6 +3,7 @@ #![stable(feature = "rust1", since = "1.0.0")] use crate::ascii; +use crate::error::Error; use crate::intrinsics; use crate::mem; use crate::ops::{Add, Mul, Sub}; @@ -57,6 +58,15 @@ pub use wrapping::Wrapping; #[cfg(not(no_fp_fmt_parse))] pub use dec2flt::ParseFloatError; +#[cfg(not(no_fp_fmt_parse))] +#[stable(feature = "rust1", since = "1.0.0")] +impl Error for ParseFloatError { + #[allow(deprecated)] + fn description(&self) -> &str { + self.__description() + } +} + #[stable(feature = "rust1", since = "1.0.0")] pub use error::ParseIntError; @@ -101,6 +111,9 @@ macro_rules! widening_impl { /// This returns the low-order (wrapping) bits and the high-order (overflow) bits /// of the result as two separate values, in that order. /// + /// If you also need to add a carry to the wide result, then you want + /// [`Self::carrying_mul`] instead. + /// /// # Examples /// /// Basic usage: @@ -136,6 +149,8 @@ macro_rules! widening_impl { /// additional amount of overflow. This allows for chaining together multiple /// multiplications to create "big integers" which represent larger values. /// + /// If you don't need the `carry`, then you can use [`Self::widening_mul`] instead. + /// /// # Examples /// /// Basic usage: @@ -155,6 +170,31 @@ macro_rules! widening_impl { )] /// ``` /// + /// This is the core operation needed for scalar multiplication when + /// implementing it for wider-than-native types. + /// + /// ``` + /// #![feature(bigint_helper_methods)] + /// fn scalar_mul_eq(little_endian_digits: &mut Vec<u16>, multiplicand: u16) { + /// let mut carry = 0; + /// for d in little_endian_digits.iter_mut() { + /// (*d, carry) = d.carrying_mul(multiplicand, carry); + /// } + /// if carry != 0 { + /// little_endian_digits.push(carry); + /// } + /// } + /// + /// let mut v = vec![10, 20]; + /// scalar_mul_eq(&mut v, 3); + /// assert_eq!(v, [30, 60]); + /// + /// assert_eq!(0x87654321_u64 * 0xFEED, 0x86D3D159E38D); + /// let mut v = vec![0x4321, 0x8765]; + /// scalar_mul_eq(&mut v, 0xFEED); + /// assert_eq!(v, [0xE38D, 0xD159, 0x86D3]); + /// ``` + /// /// If `carry` is zero, this is similar to [`overflowing_mul`](Self::overflowing_mul), /// except that it gives the value of the overflow instead of just whether one happened: /// @@ -582,6 +622,38 @@ impl u8 { matches!(*self, b'0'..=b'9') } + /// Checks if the value is an ASCII octal digit: + /// U+0030 '0' ..= U+0037 '7'. + /// + /// # Examples + /// + /// ``` + /// #![feature(is_ascii_octdigit)] + /// + /// let uppercase_a = b'A'; + /// let a = b'a'; + /// let zero = b'0'; + /// let seven = b'7'; + /// let nine = b'9'; + /// let percent = b'%'; + /// let lf = b'\n'; + /// + /// assert!(!uppercase_a.is_ascii_octdigit()); + /// assert!(!a.is_ascii_octdigit()); + /// assert!(zero.is_ascii_octdigit()); + /// assert!(seven.is_ascii_octdigit()); + /// assert!(!nine.is_ascii_octdigit()); + /// assert!(!percent.is_ascii_octdigit()); + /// assert!(!lf.is_ascii_octdigit()); + /// ``` + #[must_use] + #[unstable(feature = "is_ascii_octdigit", issue = "101288")] + #[rustc_const_unstable(feature = "is_ascii_octdigit", issue = "101288")] + #[inline] + pub const fn is_ascii_octdigit(&self) -> bool { + matches!(*self, b'0'..=b'7') + } + /// Checks if the value is an ASCII hexadecimal digit: /// /// - U+0030 '0' ..= U+0039 '9', or @@ -623,7 +695,7 @@ impl u8 { /// /// - U+0021 ..= U+002F `! " # $ % & ' ( ) * + , - . /`, or /// - U+003A ..= U+0040 `: ; < = > ? @`, or - /// - U+005B ..= U+0060 ``[ \ ] ^ _ ` ``, or + /// - U+005B ..= U+0060 `` [ \ ] ^ _ ` ``, or /// - U+007B ..= U+007E `{ | } ~` /// /// # Examples @@ -936,8 +1008,8 @@ impl usize { /// assert_eq!(num.classify(), FpCategory::Normal); /// assert_eq!(inf.classify(), FpCategory::Infinite); /// assert_eq!(zero.classify(), FpCategory::Zero); -/// assert_eq!(nan.classify(), FpCategory::Nan); /// assert_eq!(sub.classify(), FpCategory::Subnormal); +/// assert_eq!(nan.classify(), FpCategory::Nan); /// ``` #[derive(Copy, Clone, PartialEq, Eq, Debug)] #[stable(feature = "rust1", since = "1.0.0")] diff --git a/library/core/src/num/nonzero.rs b/library/core/src/num/nonzero.rs index 4de0a0cf5..6b6f3417f 100644 --- a/library/core/src/num/nonzero.rs +++ b/library/core/src/num/nonzero.rs @@ -56,7 +56,10 @@ macro_rules! nonzero_integers { pub const unsafe fn new_unchecked(n: $Int) -> Self { // SAFETY: this is guaranteed to be safe by the caller. unsafe { - core::intrinsics::assert_unsafe_precondition!(n != 0); + core::intrinsics::assert_unsafe_precondition!( + concat!(stringify!($Ty), "::new_unchecked requires a non-zero argument"), + (n: $Int) => n != 0 + ); Self(n) } } @@ -309,8 +312,8 @@ macro_rules! nonzero_unsigned_operations { ( $( $Ty: ident($Int: ident); )+ ) => { $( impl $Ty { - /// Add an unsigned integer to a non-zero value. - /// Check for overflow and return [`None`] on overflow + /// Adds an unsigned integer to a non-zero value. + /// Checks for overflow and returns [`None`] on overflow. /// As a consequence, the result cannot wrap to zero. /// /// @@ -346,7 +349,7 @@ macro_rules! nonzero_unsigned_operations { } } - /// Add an unsigned integer to a non-zero value. + /// Adds an unsigned integer to a non-zero value. #[doc = concat!("Return [`", stringify!($Int), "::MAX`] on overflow.")] /// /// # Examples @@ -377,7 +380,7 @@ macro_rules! nonzero_unsigned_operations { unsafe { $Ty::new_unchecked(self.get().saturating_add(other)) } } - /// Add an unsigned integer to a non-zero value, + /// Adds an unsigned integer to a non-zero value, /// assuming overflow cannot occur. /// Overflow is unchecked, and it is undefined behaviour to overflow /// *even if the result would wrap to a non-zero value*. @@ -409,7 +412,7 @@ macro_rules! nonzero_unsigned_operations { } /// Returns the smallest power of two greater than or equal to n. - /// Check for overflow and return [`None`] + /// Checks for overflow and returns [`None`] /// if the next power of two is greater than the type’s maximum value. /// As a consequence, the result cannot wrap to zero. /// @@ -450,7 +453,7 @@ macro_rules! nonzero_unsigned_operations { /// Returns the base 2 logarithm of the number, rounded down. /// /// This is the same operation as - #[doc = concat!("[`", stringify!($Int), "::log2`],")] + #[doc = concat!("[`", stringify!($Int), "::ilog2`],")] /// except that it has no failure cases to worry about /// since this value can never be zero. /// @@ -460,22 +463,22 @@ macro_rules! nonzero_unsigned_operations { /// #![feature(int_log)] #[doc = concat!("# use std::num::", stringify!($Ty), ";")] /// - #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(7).unwrap().log2(), 2);")] - #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(8).unwrap().log2(), 3);")] - #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(9).unwrap().log2(), 3);")] + #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(7).unwrap().ilog2(), 2);")] + #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(8).unwrap().ilog2(), 3);")] + #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(9).unwrap().ilog2(), 3);")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] - pub const fn log2(self) -> u32 { + pub const fn ilog2(self) -> u32 { Self::BITS - 1 - self.leading_zeros() } /// Returns the base 10 logarithm of the number, rounded down. /// /// This is the same operation as - #[doc = concat!("[`", stringify!($Int), "::log10`],")] + #[doc = concat!("[`", stringify!($Int), "::ilog10`],")] /// except that it has no failure cases to worry about /// since this value can never be zero. /// @@ -485,15 +488,15 @@ macro_rules! nonzero_unsigned_operations { /// #![feature(int_log)] #[doc = concat!("# use std::num::", stringify!($Ty), ";")] /// - #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(99).unwrap().log10(), 1);")] - #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(100).unwrap().log10(), 2);")] - #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(101).unwrap().log10(), 2);")] + #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(99).unwrap().ilog10(), 1);")] + #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(100).unwrap().ilog10(), 2);")] + #[doc = concat!("assert_eq!(", stringify!($Ty), "::new(101).unwrap().ilog10(), 2);")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] - pub const fn log10(self) -> u32 { + pub const fn ilog10(self) -> u32 { super::int_log10::$Int(self.0) } } @@ -545,7 +548,7 @@ macro_rules! nonzero_signed_operations { } /// Checked absolute value. - /// Check for overflow and returns [`None`] if + /// Checks for overflow and returns [`None`] if #[doc = concat!("`self == ", stringify!($Int), "::MIN`.")] /// The result cannot be zero. /// @@ -721,6 +724,160 @@ macro_rules! nonzero_signed_operations { // SAFETY: absolute value of nonzero cannot yield zero values. unsafe { $Uty::new_unchecked(self.get().unsigned_abs()) } } + + /// Returns `true` if `self` is negative and `false` if the + /// number is positive. + /// + /// # Example + /// + /// ``` + /// #![feature(nonzero_negation_ops)] + /// + #[doc = concat!("# use std::num::", stringify!($Ty), ";")] + /// # fn main() { test().unwrap(); } + /// # fn test() -> Option<()> { + #[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")] + #[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")] + /// + /// assert!(neg_five.is_negative()); + /// assert!(!pos_five.is_negative()); + /// # Some(()) + /// # } + /// ``` + #[must_use] + #[inline] + #[unstable(feature = "nonzero_negation_ops", issue = "102443")] + pub const fn is_negative(self) -> bool { + self.get().is_negative() + } + + /// Checked negation. Computes `-self`, returning `None` if `self == i32::MIN`. + /// + /// # Example + /// + /// ``` + /// #![feature(nonzero_negation_ops)] + /// + #[doc = concat!("# use std::num::", stringify!($Ty), ";")] + /// # fn main() { test().unwrap(); } + /// # fn test() -> Option<()> { + #[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")] + #[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")] + #[doc = concat!("let min = ", stringify!($Ty), "::new(", + stringify!($Int), "::MIN)?;")] + /// + /// assert_eq!(pos_five.checked_neg(), Some(neg_five)); + /// assert_eq!(min.checked_neg(), None); + /// # Some(()) + /// # } + /// ``` + #[inline] + #[unstable(feature = "nonzero_negation_ops", issue = "102443")] + pub const fn checked_neg(self) -> Option<$Ty> { + if let Some(result) = self.get().checked_neg() { + // SAFETY: negation of nonzero cannot yield zero values. + return Some(unsafe { $Ty::new_unchecked(result) }); + } + None + } + + /// Negates self, overflowing if this is equal to the minimum value. + /// + #[doc = concat!("See [`", stringify!($Int), "::overflowing_neg`]")] + /// for documentation on overflow behaviour. + /// + /// # Example + /// + /// ``` + /// #![feature(nonzero_negation_ops)] + /// + #[doc = concat!("# use std::num::", stringify!($Ty), ";")] + /// # fn main() { test().unwrap(); } + /// # fn test() -> Option<()> { + #[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")] + #[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")] + #[doc = concat!("let min = ", stringify!($Ty), "::new(", + stringify!($Int), "::MIN)?;")] + /// + /// assert_eq!(pos_five.overflowing_neg(), (neg_five, false)); + /// assert_eq!(min.overflowing_neg(), (min, true)); + /// # Some(()) + /// # } + /// ``` + #[inline] + #[unstable(feature = "nonzero_negation_ops", issue = "102443")] + pub const fn overflowing_neg(self) -> ($Ty, bool) { + let (result, overflow) = self.get().overflowing_neg(); + // SAFETY: negation of nonzero cannot yield zero values. + ((unsafe { $Ty::new_unchecked(result) }), overflow) + } + + /// Saturating negation. Computes `-self`, returning `MAX` if + /// `self == i32::MIN` instead of overflowing. + /// + /// # Example + /// + /// ``` + /// #![feature(nonzero_negation_ops)] + /// + #[doc = concat!("# use std::num::", stringify!($Ty), ";")] + /// # fn main() { test().unwrap(); } + /// # fn test() -> Option<()> { + #[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")] + #[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")] + #[doc = concat!("let min = ", stringify!($Ty), "::new(", + stringify!($Int), "::MIN)?;")] + #[doc = concat!("let min_plus_one = ", stringify!($Ty), "::new(", + stringify!($Int), "::MIN + 1)?;")] + #[doc = concat!("let max = ", stringify!($Ty), "::new(", + stringify!($Int), "::MAX)?;")] + /// + /// assert_eq!(pos_five.saturating_neg(), neg_five); + /// assert_eq!(min.saturating_neg(), max); + /// assert_eq!(max.saturating_neg(), min_plus_one); + /// # Some(()) + /// # } + /// ``` + #[inline] + #[unstable(feature = "nonzero_negation_ops", issue = "102443")] + pub const fn saturating_neg(self) -> $Ty { + if let Some(result) = self.checked_neg() { + return result; + } + $Ty::MAX + } + + /// Wrapping (modular) negation. Computes `-self`, wrapping around at the boundary + /// of the type. + /// + #[doc = concat!("See [`", stringify!($Int), "::wrapping_neg`]")] + /// for documentation on overflow behaviour. + /// + /// # Example + /// + /// ``` + /// #![feature(nonzero_negation_ops)] + /// + #[doc = concat!("# use std::num::", stringify!($Ty), ";")] + /// # fn main() { test().unwrap(); } + /// # fn test() -> Option<()> { + #[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")] + #[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")] + #[doc = concat!("let min = ", stringify!($Ty), "::new(", + stringify!($Int), "::MIN)?;")] + /// + /// assert_eq!(pos_five.wrapping_neg(), neg_five); + /// assert_eq!(min.wrapping_neg(), min); + /// # Some(()) + /// # } + /// ``` + #[inline] + #[unstable(feature = "nonzero_negation_ops", issue = "102443")] + pub const fn wrapping_neg(self) -> $Ty { + let result = self.get().wrapping_neg(); + // SAFETY: negation of nonzero cannot yield zero values. + unsafe { $Ty::new_unchecked(result) } + } } )+ } @@ -740,8 +897,8 @@ macro_rules! nonzero_unsigned_signed_operations { ( $( $signedness:ident $Ty: ident($Int: ty); )+ ) => { $( impl $Ty { - /// Multiply two non-zero integers together. - /// Check for overflow and return [`None`] on overflow. + /// Multiplies two non-zero integers together. + /// Checks for overflow and returns [`None`] on overflow. /// As a consequence, the result cannot wrap to zero. /// /// # Examples @@ -777,7 +934,7 @@ macro_rules! nonzero_unsigned_signed_operations { } } - /// Multiply two non-zero integers together. + /// Multiplies two non-zero integers together. #[doc = concat!("Return [`", stringify!($Int), "::MAX`] on overflow.")] /// /// # Examples @@ -809,7 +966,7 @@ macro_rules! nonzero_unsigned_signed_operations { unsafe { $Ty::new_unchecked(self.get().saturating_mul(other.get())) } } - /// Multiply two non-zero integers together, + /// Multiplies two non-zero integers together, /// assuming overflow cannot occur. /// Overflow is unchecked, and it is undefined behaviour to overflow /// *even if the result would wrap to a non-zero value*. @@ -849,8 +1006,8 @@ macro_rules! nonzero_unsigned_signed_operations { unsafe { $Ty::new_unchecked(self.get().unchecked_mul(other.get())) } } - /// Raise non-zero value to an integer power. - /// Check for overflow and return [`None`] on overflow. + /// Raises non-zero value to an integer power. + /// Checks for overflow and returns [`None`] on overflow. /// As a consequence, the result cannot wrap to zero. /// /// # Examples diff --git a/library/core/src/num/uint_macros.rs b/library/core/src/num/uint_macros.rs index 733655442..335cc5124 100644 --- a/library/core/src/num/uint_macros.rs +++ b/library/core/src/num/uint_macros.rs @@ -474,13 +474,12 @@ macro_rules! uint_impl { /// Basic usage: /// /// ``` - /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_signed(2), Some(3));")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_signed(-2), None);")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add_signed(3), None);")] /// ``` - #[unstable(feature = "mixed_integer_ops", issue = "87840")] - #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[stable(feature = "mixed_integer_ops", since = "1.66.0")] + #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -688,104 +687,69 @@ macro_rules! uint_impl { /// rounded down. /// /// This method might not be optimized owing to implementation details; - /// `log2` can produce results more efficiently for base 2, and `log10` + /// `ilog2` can produce results more efficiently for base 2, and `ilog10` /// can produce results more efficiently for base 10. /// /// # Panics /// - /// When the number is zero, or if the base is not at least 2; - /// it panics in debug mode and the return value is 0 in release mode. + /// This function will panic if `self` is zero, or if `base` is less then 2. /// /// # Examples /// /// ``` /// #![feature(int_log)] - #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".log(5), 1);")] + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".ilog(5), 1);")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] - #[rustc_inherit_overflow_checks] - #[allow(arithmetic_overflow)] - pub const fn log(self, base: Self) -> u32 { - match self.checked_log(base) { - Some(n) => n, - None => { - // In debug builds, trigger a panic on None. - // This should optimize completely out in release builds. - let _ = Self::MAX + 1; - - 0 - }, - } + pub const fn ilog(self, base: Self) -> u32 { + assert!(base >= 2, "base of integer logarithm must be at least 2"); + self.checked_ilog(base).expect("argument of integer logarithm must be positive") } /// Returns the base 2 logarithm of the number, rounded down. /// /// # Panics /// - /// When the number is zero it panics in debug mode and - /// the return value is 0 in release mode. + /// This function will panic if `self` is zero. /// /// # Examples /// /// ``` /// #![feature(int_log)] - #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".log2(), 1);")] + #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".ilog2(), 1);")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] - #[rustc_inherit_overflow_checks] - #[allow(arithmetic_overflow)] - pub const fn log2(self) -> u32 { - match self.checked_log2() { - Some(n) => n, - None => { - // In debug builds, trigger a panic on None. - // This should optimize completely out in release builds. - let _ = Self::MAX + 1; - - 0 - }, - } + pub const fn ilog2(self) -> u32 { + self.checked_ilog2().expect("argument of integer logarithm must be positive") } /// Returns the base 10 logarithm of the number, rounded down. /// /// # Panics /// - /// When the number is zero it panics in debug mode and the - /// return value is 0 in release mode. + /// This function will panic if `self` is zero. /// /// # Example /// /// ``` /// #![feature(int_log)] - #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".log10(), 1);")] + #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".ilog10(), 1);")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] - #[rustc_inherit_overflow_checks] - #[allow(arithmetic_overflow)] - pub const fn log10(self) -> u32 { - match self.checked_log10() { - Some(n) => n, - None => { - // In debug builds, trigger a panic on None. - // This should optimize completely out in release builds. - let _ = Self::MAX + 1; - - 0 - }, - } + pub const fn ilog10(self) -> u32 { + self.checked_ilog10().expect("argument of integer logarithm must be positive") } /// Returns the logarithm of the number with respect to an arbitrary base, @@ -794,20 +758,20 @@ macro_rules! uint_impl { /// Returns `None` if the number is zero, or if the base is not at least 2. /// /// This method might not be optimized owing to implementation details; - /// `checked_log2` can produce results more efficiently for base 2, and - /// `checked_log10` can produce results more efficiently for base 10. + /// `checked_ilog2` can produce results more efficiently for base 2, and + /// `checked_ilog10` can produce results more efficiently for base 10. /// /// # Examples /// /// ``` /// #![feature(int_log)] - #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_log(5), Some(1));")] + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(5), Some(1));")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] - pub const fn checked_log(self, base: Self) -> Option<u32> { + pub const fn checked_ilog(self, base: Self) -> Option<u32> { if self <= 0 || base <= 1 { None } else { @@ -816,7 +780,7 @@ macro_rules! uint_impl { // Optimization for 128 bit wide integers. if Self::BITS == 128 { - let b = Self::log2(self) / (Self::log2(base) + 1); + let b = Self::ilog2(self) / (Self::ilog2(base) + 1); n += b; r /= base.pow(b as u32); } @@ -837,15 +801,15 @@ macro_rules! uint_impl { /// /// ``` /// #![feature(int_log)] - #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_log2(), Some(1));")] + #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_ilog2(), Some(1));")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] - pub const fn checked_log2(self) -> Option<u32> { + pub const fn checked_ilog2(self) -> Option<u32> { if let Some(x) = <$NonZeroT>::new(self) { - Some(x.log2()) + Some(x.ilog2()) } else { None } @@ -859,15 +823,15 @@ macro_rules! uint_impl { /// /// ``` /// #![feature(int_log)] - #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_log10(), Some(1));")] + #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_ilog10(), Some(1));")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] - pub const fn checked_log10(self) -> Option<u32> { + pub const fn checked_ilog10(self) -> Option<u32> { if let Some(x) = <$NonZeroT>::new(self) { - Some(x.log10()) + Some(x.ilog10()) } else { None } @@ -1026,7 +990,7 @@ macro_rules! uint_impl { // squaring the base afterwards is not necessary and may cause a // needless overflow. - Some(try_opt!(acc.checked_mul(base))) + acc.checked_mul(base) } /// Saturating integer addition. Computes `self + rhs`, saturating at @@ -1057,13 +1021,12 @@ macro_rules! uint_impl { /// Basic usage: /// /// ``` - /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_signed(2), 3);")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_signed(-2), 0);")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).saturating_add_signed(4), ", stringify!($SelfT), "::MAX);")] /// ``` - #[unstable(feature = "mixed_integer_ops", issue = "87840")] - #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[stable(feature = "mixed_integer_ops", since = "1.66.0")] + #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -1198,13 +1161,12 @@ macro_rules! uint_impl { /// Basic usage: /// /// ``` - /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_add_signed(2), 3);")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_add_signed(-2), ", stringify!($SelfT), "::MAX);")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).wrapping_add_signed(4), 1);")] /// ``` - #[unstable(feature = "mixed_integer_ops", issue = "87840")] - #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[stable(feature = "mixed_integer_ops", since = "1.66.0")] + #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -1494,7 +1456,6 @@ macro_rules! uint_impl { /// Basic usage /// /// ``` - /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (0, true));")] /// ``` @@ -1508,37 +1469,42 @@ macro_rules! uint_impl { (a as Self, b) } - /// Calculates `self + rhs + carry` without the ability to overflow. + /// Calculates `self` + `rhs` + `carry` and returns a tuple containing + /// the sum and the output carry. /// - /// Performs "ternary addition" which takes in an extra bit to add, and may return an - /// additional bit of overflow. This allows for chaining together multiple additions - /// to create "big integers" which represent larger values. + /// Performs "ternary addition" of two integer operands and a carry-in + /// bit, and returns an output integer and a carry-out bit. This allows + /// chaining together multiple additions to create a wider addition, and + /// can be useful for bignum addition. /// #[doc = concat!("This can be thought of as a ", stringify!($BITS), "-bit \"full adder\", in the electronics sense.")] /// - /// # Examples + /// If the input carry is false, this method is equivalent to + /// [`overflowing_add`](Self::overflowing_add), and the output carry is + /// equal to the overflow flag. Note that although carry and overflow + /// flags are similar for unsigned integers, they are different for + /// signed integers. /// - /// Basic usage + /// # Examples /// /// ``` /// #![feature(bigint_helper_methods)] - #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".carrying_add(2, false), (7, false));")] - #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".carrying_add(2, true), (8, false));")] - #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, false), (0, true));")] - #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(0, true), (0, true));")] - #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, true), (1, true));")] - #[doc = concat!("assert_eq!(", - stringify!($SelfT), "::MAX.carrying_add(", stringify!($SelfT), "::MAX, true), ", - "(", stringify!($SelfT), "::MAX, true));" - )] - /// ``` /// - /// If `carry` is false, this method is equivalent to [`overflowing_add`](Self::overflowing_add): + #[doc = concat!("// 3 MAX (a = 3 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")] + #[doc = concat!("// + 5 7 (b = 5 × 2^", stringify!($BITS), " + 7)")] + /// // --------- + #[doc = concat!("// 9 6 (sum = 9 × 2^", stringify!($BITS), " + 6)")] /// - /// ``` - /// #![feature(bigint_helper_methods)] - #[doc = concat!("assert_eq!(5_", stringify!($SelfT), ".carrying_add(2, false), 5_", stringify!($SelfT), ".overflowing_add(2));")] - #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, false), ", stringify!($SelfT), "::MAX.overflowing_add(1));")] + #[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (3, ", stringify!($SelfT), "::MAX);")] + #[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (5, 7);")] + /// let carry0 = false; + /// + /// let (sum0, carry1) = a0.carrying_add(b0, carry0); + /// assert_eq!(carry1, true); + /// let (sum1, carry2) = a1.carrying_add(b1, carry1); + /// assert_eq!(carry2, false); + /// + /// assert_eq!((sum1, sum0), (9, 6)); /// ``` #[unstable(feature = "bigint_helper_methods", issue = "85532")] #[rustc_const_unstable(feature = "const_bigint_helper_methods", issue = "85532")] @@ -1564,13 +1530,12 @@ macro_rules! uint_impl { /// Basic usage: /// /// ``` - /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_signed(2), (3, false));")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_signed(-2), (", stringify!($SelfT), "::MAX, true));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_add_signed(4), (1, true));")] /// ``` - #[unstable(feature = "mixed_integer_ops", issue = "87840")] - #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[stable(feature = "mixed_integer_ops", since = "1.66.0")] + #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] @@ -1590,7 +1555,6 @@ macro_rules! uint_impl { /// Basic usage /// /// ``` - /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")] #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".overflowing_sub(1), (", stringify!($SelfT), "::MAX, true));")] /// ``` @@ -1604,22 +1568,35 @@ macro_rules! uint_impl { (a as Self, b) } - /// Calculates `self - rhs - borrow` without the ability to overflow. + /// Calculates `self` − `rhs` − `borrow` and returns a tuple + /// containing the difference and the output borrow. /// - /// Performs "ternary subtraction" which takes in an extra bit to subtract, and may return - /// an additional bit of overflow. This allows for chaining together multiple subtractions - /// to create "big integers" which represent larger values. + /// Performs "ternary subtraction" by subtracting both an integer + /// operand and a borrow-in bit from `self`, and returns an output + /// integer and a borrow-out bit. This allows chaining together multiple + /// subtractions to create a wider subtraction, and can be useful for + /// bignum subtraction. /// /// # Examples /// - /// Basic usage - /// /// ``` /// #![feature(bigint_helper_methods)] - #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".borrowing_sub(2, false), (3, false));")] - #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".borrowing_sub(2, true), (2, false));")] - #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".borrowing_sub(1, false), (", stringify!($SelfT), "::MAX, true));")] - #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".borrowing_sub(1, true), (", stringify!($SelfT), "::MAX - 1, true));")] + /// + #[doc = concat!("// 9 6 (a = 9 × 2^", stringify!($BITS), " + 6)")] + #[doc = concat!("// - 5 7 (b = 5 × 2^", stringify!($BITS), " + 7)")] + /// // --------- + #[doc = concat!("// 3 MAX (diff = 3 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")] + /// + #[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (9, 6);")] + #[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (5, 7);")] + /// let borrow0 = false; + /// + /// let (diff0, borrow1) = a0.borrowing_sub(b0, borrow0); + /// assert_eq!(borrow1, true); + /// let (diff1, borrow2) = a1.borrowing_sub(b1, borrow1); + /// assert_eq!(borrow2, false); + /// + #[doc = concat!("assert_eq!((diff1, diff0), (3, ", stringify!($SelfT), "::MAX));")] /// ``` #[unstable(feature = "bigint_helper_methods", issue = "85532")] #[rustc_const_unstable(feature = "const_bigint_helper_methods", issue = "85532")] diff --git a/library/core/src/ops/arith.rs b/library/core/src/ops/arith.rs index e367be8c1..75c52d3ec 100644 --- a/library/core/src/ops/arith.rs +++ b/library/core/src/ops/arith.rs @@ -65,38 +65,15 @@ /// ``` #[lang = "add"] #[stable(feature = "rust1", since = "1.0.0")] -#[cfg_attr( - bootstrap, - rustc_on_unimplemented( - on( - all(_Self = "{integer}", Rhs = "{float}"), - message = "cannot add a float to an integer", - ), - on( - all(_Self = "{float}", Rhs = "{integer}"), - message = "cannot add an integer to a float", - ), - message = "cannot add `{Rhs}` to `{Self}`", - label = "no implementation for `{Self} + {Rhs}`" - ) -)] -#[cfg_attr( - not(bootstrap), - rustc_on_unimplemented( - on( - all(_Self = "{integer}", Rhs = "{float}"), - message = "cannot add a float to an integer", - ), - on( - all(_Self = "{float}", Rhs = "{integer}"), - message = "cannot add an integer to a float", - ), - message = "cannot add `{Rhs}` to `{Self}`", - label = "no implementation for `{Self} + {Rhs}`", - append_const_msg, - ) +#[rustc_on_unimplemented( + on(all(_Self = "{integer}", Rhs = "{float}"), message = "cannot add a float to an integer",), + on(all(_Self = "{float}", Rhs = "{integer}"), message = "cannot add an integer to a float",), + message = "cannot add `{Rhs}` to `{Self}`", + label = "no implementation for `{Self} + {Rhs}`", + append_const_msg )] #[doc(alias = "+")] +#[const_trait] pub trait Add<Rhs = Self> { /// The resulting type after applying the `+` operator. #[stable(feature = "rust1", since = "1.0.0")] @@ -201,9 +178,11 @@ add_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 } #[stable(feature = "rust1", since = "1.0.0")] #[rustc_on_unimplemented( message = "cannot subtract `{Rhs}` from `{Self}`", - label = "no implementation for `{Self} - {Rhs}`" + label = "no implementation for `{Self} - {Rhs}`", + append_const_msg )] #[doc(alias = "-")] +#[const_trait] pub trait Sub<Rhs = Self> { /// The resulting type after applying the `-` operator. #[stable(feature = "rust1", since = "1.0.0")] @@ -333,6 +312,7 @@ sub_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 } label = "no implementation for `{Self} * {Rhs}`" )] #[doc(alias = "*")] +#[const_trait] pub trait Mul<Rhs = Self> { /// The resulting type after applying the `*` operator. #[stable(feature = "rust1", since = "1.0.0")] @@ -466,6 +446,7 @@ mul_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 } label = "no implementation for `{Self} / {Rhs}`" )] #[doc(alias = "/")] +#[const_trait] pub trait Div<Rhs = Self> { /// The resulting type after applying the `/` operator. #[stable(feature = "rust1", since = "1.0.0")] @@ -568,6 +549,7 @@ div_impl_float! { f32 f64 } label = "no implementation for `{Self} % {Rhs}`" )] #[doc(alias = "%")] +#[const_trait] pub trait Rem<Rhs = Self> { /// The resulting type after applying the `%` operator. #[stable(feature = "rust1", since = "1.0.0")] @@ -682,6 +664,7 @@ rem_impl_float! { f32 f64 } #[lang = "neg"] #[stable(feature = "rust1", since = "1.0.0")] #[doc(alias = "-")] +#[const_trait] pub trait Neg { /// The resulting type after applying the `-` operator. #[stable(feature = "rust1", since = "1.0.0")] @@ -755,6 +738,7 @@ neg_impl! { isize i8 i16 i32 i64 i128 f32 f64 } )] #[doc(alias = "+")] #[doc(alias = "+=")] +#[const_trait] pub trait AddAssign<Rhs = Self> { /// Performs the `+=` operation. /// @@ -822,6 +806,7 @@ add_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 } )] #[doc(alias = "-")] #[doc(alias = "-=")] +#[const_trait] pub trait SubAssign<Rhs = Self> { /// Performs the `-=` operation. /// @@ -880,6 +865,7 @@ sub_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 } )] #[doc(alias = "*")] #[doc(alias = "*=")] +#[const_trait] pub trait MulAssign<Rhs = Self> { /// Performs the `*=` operation. /// @@ -938,6 +924,7 @@ mul_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 } )] #[doc(alias = "/")] #[doc(alias = "/=")] +#[const_trait] pub trait DivAssign<Rhs = Self> { /// Performs the `/=` operation. /// @@ -999,6 +986,7 @@ div_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 } )] #[doc(alias = "%")] #[doc(alias = "%=")] +#[const_trait] pub trait RemAssign<Rhs = Self> { /// Performs the `%=` operation. /// diff --git a/library/core/src/ops/bit.rs b/library/core/src/ops/bit.rs index 7c664226f..327009801 100644 --- a/library/core/src/ops/bit.rs +++ b/library/core/src/ops/bit.rs @@ -31,6 +31,7 @@ #[lang = "not"] #[stable(feature = "rust1", since = "1.0.0")] #[doc(alias = "!")] +#[const_trait] pub trait Not { /// The resulting type after applying the `!` operator. #[stable(feature = "rust1", since = "1.0.0")] @@ -143,6 +144,7 @@ impl const Not for ! { message = "no implementation for `{Self} & {Rhs}`", label = "no implementation for `{Self} & {Rhs}`" )] +#[const_trait] pub trait BitAnd<Rhs = Self> { /// The resulting type after applying the `&` operator. #[stable(feature = "rust1", since = "1.0.0")] @@ -244,6 +246,7 @@ bitand_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 } message = "no implementation for `{Self} | {Rhs}`", label = "no implementation for `{Self} | {Rhs}`" )] +#[const_trait] pub trait BitOr<Rhs = Self> { /// The resulting type after applying the `|` operator. #[stable(feature = "rust1", since = "1.0.0")] @@ -345,6 +348,7 @@ bitor_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 } message = "no implementation for `{Self} ^ {Rhs}`", label = "no implementation for `{Self} ^ {Rhs}`" )] +#[const_trait] pub trait BitXor<Rhs = Self> { /// The resulting type after applying the `^` operator. #[stable(feature = "rust1", since = "1.0.0")] @@ -445,6 +449,7 @@ bitxor_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 } message = "no implementation for `{Self} << {Rhs}`", label = "no implementation for `{Self} << {Rhs}`" )] +#[const_trait] pub trait Shl<Rhs = Self> { /// The resulting type after applying the `<<` operator. #[stable(feature = "rust1", since = "1.0.0")] @@ -564,6 +569,7 @@ shl_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 isize i128 } message = "no implementation for `{Self} >> {Rhs}`", label = "no implementation for `{Self} >> {Rhs}`" )] +#[const_trait] pub trait Shr<Rhs = Self> { /// The resulting type after applying the `>>` operator. #[stable(feature = "rust1", since = "1.0.0")] @@ -692,6 +698,7 @@ shr_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize } message = "no implementation for `{Self} &= {Rhs}`", label = "no implementation for `{Self} &= {Rhs}`" )] +#[const_trait] pub trait BitAndAssign<Rhs = Self> { /// Performs the `&=` operation. /// @@ -764,6 +771,7 @@ bitand_assign_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 } message = "no implementation for `{Self} |= {Rhs}`", label = "no implementation for `{Self} |= {Rhs}`" )] +#[const_trait] pub trait BitOrAssign<Rhs = Self> { /// Performs the `|=` operation. /// @@ -836,6 +844,7 @@ bitor_assign_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 } message = "no implementation for `{Self} ^= {Rhs}`", label = "no implementation for `{Self} ^= {Rhs}`" )] +#[const_trait] pub trait BitXorAssign<Rhs = Self> { /// Performs the `^=` operation. /// @@ -906,6 +915,7 @@ bitxor_assign_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 } message = "no implementation for `{Self} <<= {Rhs}`", label = "no implementation for `{Self} <<= {Rhs}`" )] +#[const_trait] pub trait ShlAssign<Rhs = Self> { /// Performs the `<<=` operation. /// @@ -989,6 +999,7 @@ shl_assign_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize } message = "no implementation for `{Self} >>= {Rhs}`", label = "no implementation for `{Self} >>= {Rhs}`" )] +#[const_trait] pub trait ShrAssign<Rhs = Self> { /// Performs the `>>=` operation. /// diff --git a/library/core/src/ops/control_flow.rs b/library/core/src/ops/control_flow.rs index b1f5559dc..72ebe653c 100644 --- a/library/core/src/ops/control_flow.rs +++ b/library/core/src/ops/control_flow.rs @@ -95,7 +95,8 @@ pub enum ControlFlow<B, C = ()> { } #[unstable(feature = "try_trait_v2", issue = "84277")] -impl<B, C> ops::Try for ControlFlow<B, C> { +#[rustc_const_unstable(feature = "const_convert", issue = "88674")] +impl<B, C> const ops::Try for ControlFlow<B, C> { type Output = C; type Residual = ControlFlow<B, convert::Infallible>; @@ -114,7 +115,8 @@ impl<B, C> ops::Try for ControlFlow<B, C> { } #[unstable(feature = "try_trait_v2", issue = "84277")] -impl<B, C> ops::FromResidual for ControlFlow<B, C> { +#[rustc_const_unstable(feature = "const_convert", issue = "88674")] +impl<B, C> const ops::FromResidual for ControlFlow<B, C> { #[inline] fn from_residual(residual: ControlFlow<B, convert::Infallible>) -> Self { match residual { @@ -124,7 +126,8 @@ impl<B, C> ops::FromResidual for ControlFlow<B, C> { } #[unstable(feature = "try_trait_v2_residual", issue = "91285")] -impl<B, C> ops::Residual<C> for ControlFlow<B, convert::Infallible> { +#[rustc_const_unstable(feature = "const_try", issue = "74935")] +impl<B, C> const ops::Residual<C> for ControlFlow<B, convert::Infallible> { type TryType = ControlFlow<B, C>; } diff --git a/library/core/src/ops/deref.rs b/library/core/src/ops/deref.rs index d68932402..4f4c99c4a 100644 --- a/library/core/src/ops/deref.rs +++ b/library/core/src/ops/deref.rs @@ -61,6 +61,7 @@ #[doc(alias = "&*")] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_diagnostic_item = "Deref"] +#[cfg_attr(not(bootstrap), const_trait)] pub trait Deref { /// The resulting type after dereferencing. #[stable(feature = "rust1", since = "1.0.0")] @@ -169,6 +170,7 @@ impl<T: ?Sized> const Deref for &mut T { #[lang = "deref_mut"] #[doc(alias = "*")] #[stable(feature = "rust1", since = "1.0.0")] +#[const_trait] pub trait DerefMut: Deref { /// Mutably dereferences the value. #[stable(feature = "rust1", since = "1.0.0")] diff --git a/library/core/src/ops/drop.rs b/library/core/src/ops/drop.rs index aa654aa55..a2c3d978c 100644 --- a/library/core/src/ops/drop.rs +++ b/library/core/src/ops/drop.rs @@ -134,6 +134,7 @@ /// these types cannot have destructors. #[lang = "drop"] #[stable(feature = "rust1", since = "1.0.0")] +#[const_trait] pub trait Drop { /// Executes the destructor for this type. /// @@ -156,7 +157,7 @@ pub trait Drop { /// handled by the compiler, but when using unsafe code, can sometimes occur /// unintentionally, particularly when using [`ptr::drop_in_place`]. /// - /// [E0040]: ../../error-index.html#E0040 + /// [E0040]: ../../error_codes/E0040.html /// [`panic!`]: crate::panic! /// [`mem::drop`]: drop /// [`ptr::drop_in_place`]: crate::ptr::drop_in_place diff --git a/library/core/src/ops/function.rs b/library/core/src/ops/function.rs index c5a194b7d..2e0a752c8 100644 --- a/library/core/src/ops/function.rs +++ b/library/core/src/ops/function.rs @@ -71,6 +71,7 @@ )] #[fundamental] // so that regex can rely that `&str: !FnMut` #[must_use = "closures are lazy and do nothing unless called"] +#[cfg_attr(not(bootstrap), const_trait)] pub trait Fn<Args>: FnMut<Args> { /// Performs the call operation. #[unstable(feature = "fn_traits", issue = "29625")] @@ -158,6 +159,7 @@ pub trait Fn<Args>: FnMut<Args> { )] #[fundamental] // so that regex can rely that `&str: !FnMut` #[must_use = "closures are lazy and do nothing unless called"] +#[cfg_attr(not(bootstrap), const_trait)] pub trait FnMut<Args>: FnOnce<Args> { /// Performs the call operation. #[unstable(feature = "fn_traits", issue = "29625")] @@ -237,6 +239,7 @@ pub trait FnMut<Args>: FnOnce<Args> { )] #[fundamental] // so that regex can rely that `&str: !FnMut` #[must_use = "closures are lazy and do nothing unless called"] +#[cfg_attr(not(bootstrap), const_trait)] pub trait FnOnce<Args> { /// The returned type after the call operator is used. #[lang = "fn_once_output"] @@ -250,9 +253,10 @@ pub trait FnOnce<Args> { mod impls { #[stable(feature = "rust1", since = "1.0.0")] - impl<A, F: ?Sized> Fn<A> for &F + #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] + impl<A, F: ?Sized> const Fn<A> for &F where - F: Fn<A>, + F: ~const Fn<A>, { extern "rust-call" fn call(&self, args: A) -> F::Output { (**self).call(args) @@ -260,9 +264,10 @@ mod impls { } #[stable(feature = "rust1", since = "1.0.0")] - impl<A, F: ?Sized> FnMut<A> for &F + #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] + impl<A, F: ?Sized> const FnMut<A> for &F where - F: Fn<A>, + F: ~const Fn<A>, { extern "rust-call" fn call_mut(&mut self, args: A) -> F::Output { (**self).call(args) @@ -270,9 +275,10 @@ mod impls { } #[stable(feature = "rust1", since = "1.0.0")] - impl<A, F: ?Sized> FnOnce<A> for &F + #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] + impl<A, F: ?Sized> const FnOnce<A> for &F where - F: Fn<A>, + F: ~const Fn<A>, { type Output = F::Output; @@ -282,9 +288,10 @@ mod impls { } #[stable(feature = "rust1", since = "1.0.0")] - impl<A, F: ?Sized> FnMut<A> for &mut F + #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] + impl<A, F: ?Sized> const FnMut<A> for &mut F where - F: FnMut<A>, + F: ~const FnMut<A>, { extern "rust-call" fn call_mut(&mut self, args: A) -> F::Output { (*self).call_mut(args) @@ -292,9 +299,10 @@ mod impls { } #[stable(feature = "rust1", since = "1.0.0")] - impl<A, F: ?Sized> FnOnce<A> for &mut F + #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] + impl<A, F: ?Sized> const FnOnce<A> for &mut F where - F: FnMut<A>, + F: ~const FnMut<A>, { type Output = F::Output; extern "rust-call" fn call_once(self, args: A) -> F::Output { diff --git a/library/core/src/ops/generator.rs b/library/core/src/ops/generator.rs index b651b7b23..fee4beb1e 100644 --- a/library/core/src/ops/generator.rs +++ b/library/core/src/ops/generator.rs @@ -83,7 +83,6 @@ pub trait Generator<R = ()> { /// `return` statement or implicitly as the last expression of a generator /// literal. For example futures would use this as `Result<T, E>` as it /// represents a completed future. - #[lang = "generator_return"] type Return; /// Resumes the execution of this generator. diff --git a/library/core/src/ops/index.rs b/library/core/src/ops/index.rs index e2e569cb7..dd4e3ac1c 100644 --- a/library/core/src/ops/index.rs +++ b/library/core/src/ops/index.rs @@ -55,6 +55,7 @@ #[doc(alias = "]")] #[doc(alias = "[")] #[doc(alias = "[]")] +#[cfg_attr(not(bootstrap), const_trait)] pub trait Index<Idx: ?Sized> { /// The returned type after indexing. #[stable(feature = "rust1", since = "1.0.0")] @@ -163,6 +164,7 @@ see chapter in The Book <https://doc.rust-lang.org/book/ch08-02-strings.html#ind #[doc(alias = "[")] #[doc(alias = "]")] #[doc(alias = "[]")] +#[cfg_attr(not(bootstrap), const_trait)] pub trait IndexMut<Idx: ?Sized>: Index<Idx> { /// Performs the mutable indexing (`container[index]`) operation. /// diff --git a/library/core/src/ops/index_range.rs b/library/core/src/ops/index_range.rs new file mode 100644 index 000000000..3e06776d2 --- /dev/null +++ b/library/core/src/ops/index_range.rs @@ -0,0 +1,171 @@ +use crate::intrinsics::{assert_unsafe_precondition, unchecked_add, unchecked_sub}; +use crate::iter::{FusedIterator, TrustedLen}; + +/// Like a `Range<usize>`, but with a safety invariant that `start <= end`. +/// +/// This means that `end - start` cannot overflow, allowing some μoptimizations. +/// +/// (Normal `Range` code needs to handle degenerate ranges like `10..0`, +/// which takes extra checks compared to only handling the canonical form.) +#[derive(Clone, Debug, PartialEq, Eq)] +pub(crate) struct IndexRange { + start: usize, + end: usize, +} + +impl IndexRange { + /// # Safety + /// - `start <= end` + #[inline] + pub const unsafe fn new_unchecked(start: usize, end: usize) -> Self { + // SAFETY: comparisons on usize are pure + unsafe { + assert_unsafe_precondition!( + "IndexRange::new_unchecked requires `start <= end`", + (start: usize, end: usize) => start <= end + ) + }; + IndexRange { start, end } + } + + #[inline] + pub const fn zero_to(end: usize) -> Self { + IndexRange { start: 0, end } + } + + #[inline] + pub const fn start(&self) -> usize { + self.start + } + + #[inline] + pub const fn end(&self) -> usize { + self.end + } + + #[inline] + pub const fn len(&self) -> usize { + // SAFETY: By invariant, this cannot wrap + unsafe { unchecked_sub(self.end, self.start) } + } + + /// # Safety + /// - Can only be called when `start < end`, aka when `len > 0`. + #[inline] + unsafe fn next_unchecked(&mut self) -> usize { + debug_assert!(self.start < self.end); + + let value = self.start; + // SAFETY: The range isn't empty, so this cannot overflow + self.start = unsafe { unchecked_add(value, 1) }; + value + } + + /// # Safety + /// - Can only be called when `start < end`, aka when `len > 0`. + #[inline] + unsafe fn next_back_unchecked(&mut self) -> usize { + debug_assert!(self.start < self.end); + + // SAFETY: The range isn't empty, so this cannot overflow + let value = unsafe { unchecked_sub(self.end, 1) }; + self.end = value; + value + } + + /// Removes the first `n` items from this range, returning them as an `IndexRange`. + /// If there are fewer than `n`, then the whole range is returned and + /// `self` is left empty. + /// + /// This is designed to help implement `Iterator::advance_by`. + #[inline] + pub fn take_prefix(&mut self, n: usize) -> Self { + let mid = if n <= self.len() { + // SAFETY: We just checked that this will be between start and end, + // and thus the addition cannot overflow. + unsafe { unchecked_add(self.start, n) } + } else { + self.end + }; + let prefix = Self { start: self.start, end: mid }; + self.start = mid; + prefix + } + + /// Removes the last `n` items from this range, returning them as an `IndexRange`. + /// If there are fewer than `n`, then the whole range is returned and + /// `self` is left empty. + /// + /// This is designed to help implement `Iterator::advance_back_by`. + #[inline] + pub fn take_suffix(&mut self, n: usize) -> Self { + let mid = if n <= self.len() { + // SAFETY: We just checked that this will be between start and end, + // and thus the addition cannot overflow. + unsafe { unchecked_sub(self.end, n) } + } else { + self.start + }; + let suffix = Self { start: mid, end: self.end }; + self.end = mid; + suffix + } +} + +impl Iterator for IndexRange { + type Item = usize; + + #[inline] + fn next(&mut self) -> Option<usize> { + if self.len() > 0 { + // SAFETY: We just checked that the range is non-empty + unsafe { Some(self.next_unchecked()) } + } else { + None + } + } + + #[inline] + fn size_hint(&self) -> (usize, Option<usize>) { + let len = self.len(); + (len, Some(len)) + } + + #[inline] + fn advance_by(&mut self, n: usize) -> Result<(), usize> { + let original_len = self.len(); + self.take_prefix(n); + if n > original_len { Err(original_len) } else { Ok(()) } + } +} + +impl DoubleEndedIterator for IndexRange { + #[inline] + fn next_back(&mut self) -> Option<usize> { + if self.len() > 0 { + // SAFETY: We just checked that the range is non-empty + unsafe { Some(self.next_back_unchecked()) } + } else { + None + } + } + + #[inline] + fn advance_back_by(&mut self, n: usize) -> Result<(), usize> { + let original_len = self.len(); + self.take_suffix(n); + if n > original_len { Err(original_len) } else { Ok(()) } + } +} + +impl ExactSizeIterator for IndexRange { + #[inline] + fn len(&self) -> usize { + self.len() + } +} + +// SAFETY: Because we only deal in `usize`, our `len` is always perfect. +unsafe impl TrustedLen for IndexRange {} + +impl FusedIterator for IndexRange {} diff --git a/library/core/src/ops/mod.rs b/library/core/src/ops/mod.rs index 31c1a1d09..a5e5b13b3 100644 --- a/library/core/src/ops/mod.rs +++ b/library/core/src/ops/mod.rs @@ -146,6 +146,7 @@ mod drop; mod function; mod generator; mod index; +mod index_range; mod range; mod try_trait; mod unsize; @@ -178,6 +179,8 @@ pub use self::index::{Index, IndexMut}; #[stable(feature = "rust1", since = "1.0.0")] pub use self::range::{Range, RangeFrom, RangeFull, RangeTo}; +pub(crate) use self::index_range::IndexRange; + #[stable(feature = "inclusive_range", since = "1.26.0")] pub use self::range::{Bound, RangeBounds, RangeInclusive, RangeToInclusive}; diff --git a/library/core/src/ops/range.rs b/library/core/src/ops/range.rs index a3b148473..d29ae3561 100644 --- a/library/core/src/ops/range.rs +++ b/library/core/src/ops/range.rs @@ -677,7 +677,7 @@ pub enum Bound<T> { impl<T> Bound<T> { /// Converts from `&Bound<T>` to `Bound<&T>`. #[inline] - #[unstable(feature = "bound_as_ref", issue = "80996")] + #[stable(feature = "bound_as_ref_shared", since = "1.65.0")] pub fn as_ref(&self) -> Bound<&T> { match *self { Included(ref x) => Included(x), diff --git a/library/core/src/ops/try_trait.rs b/library/core/src/ops/try_trait.rs index 02f7f62bf..84a690468 100644 --- a/library/core/src/ops/try_trait.rs +++ b/library/core/src/ops/try_trait.rs @@ -128,7 +128,8 @@ use crate::ops::ControlFlow; )] #[doc(alias = "?")] #[lang = "Try"] -pub trait Try: FromResidual { +#[const_trait] +pub trait Try: ~const FromResidual { /// The type of the value produced by `?` when *not* short-circuiting. #[unstable(feature = "try_trait_v2", issue = "84277")] type Output; @@ -232,7 +233,7 @@ pub trait Try: FromResidual { message = "the `?` operator can only be used on `Result`s, not `Option`s, \ in {ItemContext} that returns `Result`", label = "use `.ok_or(...)?` to provide an error compatible with `{Self}`", - enclosing_scope = "this function returns a `Result`" + parent_label = "this function returns a `Result`" ), on( all( @@ -245,7 +246,7 @@ pub trait Try: FromResidual { message = "the `?` operator can only be used on `Result`s \ in {ItemContext} that returns `Result`", label = "this `?` produces `{R}`, which is incompatible with `{Self}`", - enclosing_scope = "this function returns a `Result`" + parent_label = "this function returns a `Result`" ), on( all( @@ -256,7 +257,7 @@ pub trait Try: FromResidual { message = "the `?` operator can only be used on `Option`s, not `Result`s, \ in {ItemContext} that returns `Option`", label = "use `.ok()?` if you want to discard the `{R}` error information", - enclosing_scope = "this function returns an `Option`" + parent_label = "this function returns an `Option`" ), on( all( @@ -268,7 +269,7 @@ pub trait Try: FromResidual { message = "the `?` operator can only be used on `Option`s \ in {ItemContext} that returns `Option`", label = "this `?` produces `{R}`, which is incompatible with `{Self}`", - enclosing_scope = "this function returns an `Option`" + parent_label = "this function returns an `Option`" ), on( all( @@ -279,7 +280,7 @@ pub trait Try: FromResidual { message = "the `?` operator in {ItemContext} that returns `ControlFlow<B, _>` \ can only be used on other `ControlFlow<B, _>`s (with the same Break type)", label = "this `?` produces `{R}`, which is incompatible with `{Self}`", - enclosing_scope = "this function returns a `ControlFlow`", + parent_label = "this function returns a `ControlFlow`", note = "unlike `Result`, there's no `From`-conversion performed for `ControlFlow`" ), on( @@ -291,7 +292,7 @@ pub trait Try: FromResidual { message = "the `?` operator can only be used on `ControlFlow`s \ in {ItemContext} that returns `ControlFlow`", label = "this `?` produces `{R}`, which is incompatible with `{Self}`", - enclosing_scope = "this function returns a `ControlFlow`", + parent_label = "this function returns a `ControlFlow`", ), on( all(from_desugaring = "QuestionMark"), @@ -299,11 +300,12 @@ pub trait Try: FromResidual { that returns `Result` or `Option` \ (or another type that implements `{FromResidual}`)", label = "cannot use the `?` operator in {ItemContext} that returns `{Self}`", - enclosing_scope = "this function should return `Result` or `Option` to accept `?`" + parent_label = "this function should return `Result` or `Option` to accept `?`" ), )] #[rustc_diagnostic_item = "FromResidual"] #[unstable(feature = "try_trait_v2", issue = "84277")] +#[const_trait] pub trait FromResidual<R = <Self as Try>::Residual> { /// Constructs the type from a compatible `Residual` type. /// @@ -356,10 +358,11 @@ where /// and in the other direction, /// `<Result<Infallible, E> as Residual<T>>::TryType = Result<T, E>`. #[unstable(feature = "try_trait_v2_residual", issue = "91285")] +#[const_trait] pub trait Residual<O> { /// The "return" type of this meta-function. #[unstable(feature = "try_trait_v2_residual", issue = "91285")] - type TryType: Try<Output = O, Residual = Self>; + type TryType: ~const Try<Output = O, Residual = Self>; } #[unstable(feature = "pub_crate_should_not_need_unstable_attr", issue = "none")] @@ -376,16 +379,19 @@ pub(crate) type ChangeOutputType<T, V> = <<T as Try>::Residual as Residual<V>>:: pub(crate) struct NeverShortCircuit<T>(pub T); impl<T> NeverShortCircuit<T> { - /// Wrap a binary `FnMut` to return its result wrapped in a `NeverShortCircuit`. + /// Implementation for building `ConstFnMutClosure` for wrapping the output of a ~const FnMut in a `NeverShortCircuit`. #[inline] - pub fn wrap_mut_2<A, B>(mut f: impl FnMut(A, B) -> T) -> impl FnMut(A, B) -> Self { - move |a, b| NeverShortCircuit(f(a, b)) + pub const fn wrap_mut_2_imp<A, B, F: ~const FnMut(A, B) -> T>( + f: &mut F, + (a, b): (A, B), + ) -> NeverShortCircuit<T> { + NeverShortCircuit(f(a, b)) } } pub(crate) enum NeverShortCircuitResidual {} -impl<T> Try for NeverShortCircuit<T> { +impl<T> const Try for NeverShortCircuit<T> { type Output = T; type Residual = NeverShortCircuitResidual; @@ -400,14 +406,14 @@ impl<T> Try for NeverShortCircuit<T> { } } -impl<T> FromResidual for NeverShortCircuit<T> { +impl<T> const FromResidual for NeverShortCircuit<T> { #[inline] fn from_residual(never: NeverShortCircuitResidual) -> Self { match never {} } } -impl<T> Residual<T> for NeverShortCircuitResidual { +impl<T> const Residual<T> for NeverShortCircuitResidual { type TryType = NeverShortCircuit<T>; } diff --git a/library/core/src/option.rs b/library/core/src/option.rs index bca73cb77..f284b4359 100644 --- a/library/core/src/option.rs +++ b/library/core/src/option.rs @@ -559,22 +559,25 @@ impl<T> Option<T> { /// # Examples /// /// ``` - /// #![feature(is_some_with)] + /// #![feature(is_some_and)] /// /// let x: Option<u32> = Some(2); - /// assert_eq!(x.is_some_and(|&x| x > 1), true); + /// assert_eq!(x.is_some_and(|x| x > 1), true); /// /// let x: Option<u32> = Some(0); - /// assert_eq!(x.is_some_and(|&x| x > 1), false); + /// assert_eq!(x.is_some_and(|x| x > 1), false); /// /// let x: Option<u32> = None; - /// assert_eq!(x.is_some_and(|&x| x > 1), false); + /// assert_eq!(x.is_some_and(|x| x > 1), false); /// ``` #[must_use] #[inline] - #[unstable(feature = "is_some_with", issue = "93050")] - pub fn is_some_and(&self, f: impl FnOnce(&T) -> bool) -> bool { - matches!(self, Some(x) if f(x)) + #[unstable(feature = "is_some_and", issue = "93050")] + pub fn is_some_and(self, f: impl FnOnce(T) -> bool) -> bool { + match self { + None => false, + Some(x) => f(x), + } } /// Returns `true` if the option is a [`None`] value. @@ -834,19 +837,12 @@ impl<T> Option<T> { /// /// # Examples /// - /// Converts a string to an integer, turning poorly-formed strings - /// into 0 (the default value for integers). [`parse`] converts - /// a string to any other type that implements [`FromStr`], returning - /// [`None`] on error. - /// /// ``` - /// let good_year_from_input = "1909"; - /// let bad_year_from_input = "190blarg"; - /// let good_year = good_year_from_input.parse().ok().unwrap_or_default(); - /// let bad_year = bad_year_from_input.parse().ok().unwrap_or_default(); + /// let x: Option<u32> = None; + /// let y: Option<u32> = Some(12); /// - /// assert_eq!(1909, good_year); - /// assert_eq!(0, bad_year); + /// assert_eq!(x.unwrap_or_default(), 0); + /// assert_eq!(y.unwrap_or_default(), 12); /// ``` /// /// [default value]: Default::default @@ -1189,6 +1185,12 @@ impl<T> Option<T> { /// Returns [`None`] if the option is [`None`], otherwise returns `optb`. /// + /// Arguments passed to `and` are eagerly evaluated; if you are passing the + /// result of a function call, it is recommended to use [`and_then`], which is + /// lazily evaluated. + /// + /// [`and_then`]: Option::and_then + /// /// # Examples /// /// ``` @@ -1711,8 +1713,6 @@ impl<T, U> Option<(T, U)> { /// # Examples /// /// ``` - /// #![feature(unzip_option)] - /// /// let x = Some((1, "hi")); /// let y = None::<(u8, u32)>; /// @@ -1720,8 +1720,13 @@ impl<T, U> Option<(T, U)> { /// assert_eq!(y.unzip(), (None, None)); /// ``` #[inline] - #[unstable(feature = "unzip_option", issue = "87800", reason = "recently added")] - pub const fn unzip(self) -> (Option<T>, Option<U>) { + #[stable(feature = "unzip_option", since = "1.66.0")] + #[rustc_const_unstable(feature = "const_option", issue = "67441")] + pub const fn unzip(self) -> (Option<T>, Option<U>) + where + T: ~const Destruct, + U: ~const Destruct, + { match self { Some((a, b)) => (Some(a), Some(b)), None => (None, None), @@ -2315,7 +2320,8 @@ impl<T> ops::FromResidual<ops::Yeet<()>> for Option<T> { } #[unstable(feature = "try_trait_v2_residual", issue = "91285")] -impl<T> ops::Residual<T> for Option<convert::Infallible> { +#[rustc_const_unstable(feature = "const_try", issue = "74935")] +impl<T> const ops::Residual<T> for Option<convert::Infallible> { type TryType = Option<T>; } diff --git a/library/core/src/panic/location.rs b/library/core/src/panic/location.rs index 8eefd9ff2..6dcf23dde 100644 --- a/library/core/src/panic/location.rs +++ b/library/core/src/panic/location.rs @@ -123,8 +123,9 @@ impl<'a> Location<'a> { /// ``` #[must_use] #[stable(feature = "panic_hooks", since = "1.10.0")] + #[rustc_const_unstable(feature = "const_location_fields", issue = "102911")] #[inline] - pub fn file(&self) -> &str { + pub const fn file(&self) -> &str { self.file } @@ -147,8 +148,9 @@ impl<'a> Location<'a> { /// ``` #[must_use] #[stable(feature = "panic_hooks", since = "1.10.0")] + #[rustc_const_unstable(feature = "const_location_fields", issue = "102911")] #[inline] - pub fn line(&self) -> u32 { + pub const fn line(&self) -> u32 { self.line } @@ -171,8 +173,9 @@ impl<'a> Location<'a> { /// ``` #[must_use] #[stable(feature = "panic_col", since = "1.25.0")] + #[rustc_const_unstable(feature = "const_location_fields", issue = "102911")] #[inline] - pub fn column(&self) -> u32 { + pub const fn column(&self) -> u32 { self.col } } diff --git a/library/core/src/panicking.rs b/library/core/src/panicking.rs index 7a575a88e..a9de7c94e 100644 --- a/library/core/src/panicking.rs +++ b/library/core/src/panicking.rs @@ -29,6 +29,73 @@ use crate::fmt; use crate::panic::{Location, PanicInfo}; +// First we define the two main entry points that all panics go through. +// In the end both are just convenience wrappers around `panic_impl`. + +/// The entry point for panicking with a formatted message. +/// +/// This is designed to reduce the amount of code required at the call +/// site as much as possible (so that `panic!()` has as low an impact +/// on (e.g.) the inlining of other functions as possible), by moving +/// the actual formatting into this shared place. +#[cold] +// If panic_immediate_abort, inline the abort call, +// otherwise avoid inlining because of it is cold path. +#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))] +#[cfg_attr(feature = "panic_immediate_abort", inline)] +#[track_caller] +#[lang = "panic_fmt"] // needed for const-evaluated panics +#[rustc_do_not_const_check] // hooked by const-eval +#[rustc_const_unstable(feature = "core_panic", issue = "none")] +pub const fn panic_fmt(fmt: fmt::Arguments<'_>) -> ! { + if cfg!(feature = "panic_immediate_abort") { + super::intrinsics::abort() + } + + // NOTE This function never crosses the FFI boundary; it's a Rust-to-Rust call + // that gets resolved to the `#[panic_handler]` function. + extern "Rust" { + #[lang = "panic_impl"] + fn panic_impl(pi: &PanicInfo<'_>) -> !; + } + + let pi = PanicInfo::internal_constructor(Some(&fmt), Location::caller(), true); + + // SAFETY: `panic_impl` is defined in safe Rust code and thus is safe to call. + unsafe { panic_impl(&pi) } +} + +/// Like panic_fmt, but without unwinding and track_caller to reduce the impact on codesize. +/// Also just works on `str`, as a `fmt::Arguments` needs more space to be passed. +#[cold] +#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))] +#[cfg_attr(feature = "panic_immediate_abort", inline)] +#[cfg_attr(not(bootstrap), rustc_nounwind)] +#[cfg_attr(bootstrap, rustc_allocator_nounwind)] +pub fn panic_str_nounwind(msg: &'static str) -> ! { + if cfg!(feature = "panic_immediate_abort") { + super::intrinsics::abort() + } + + // NOTE This function never crosses the FFI boundary; it's a Rust-to-Rust call + // that gets resolved to the `#[panic_handler]` function. + extern "Rust" { + #[lang = "panic_impl"] + fn panic_impl(pi: &PanicInfo<'_>) -> !; + } + + // PanicInfo with the `can_unwind` flag set to false forces an abort. + let pieces = [msg]; + let fmt = fmt::Arguments::new_v1(&pieces, &[]); + let pi = PanicInfo::internal_constructor(Some(&fmt), Location::caller(), false); + + // SAFETY: `panic_impl` is defined in safe Rust code and thus is safe to call. + unsafe { panic_impl(&pi) } +} + +// Next we define a bunch of higher-level wrappers that all bottom out in the two core functions +// above. + /// The underlying implementation of libcore's `panic!` macro when no formatting is used. #[cold] // never inline unless panic_immediate_abort to avoid code @@ -84,62 +151,17 @@ fn panic_bounds_check(index: usize, len: usize) -> ! { panic!("index out of bounds: the len is {len} but the index is {index}") } -// This function is called directly by the codegen backend, and must not have -// any extra arguments (including those synthesized by track_caller). +/// Panic because we cannot unwind out of a function. +/// +/// This function is called directly by the codegen backend, and must not have +/// any extra arguments (including those synthesized by track_caller). #[cold] #[inline(never)] #[lang = "panic_no_unwind"] // needed by codegen for panic in nounwind function +#[cfg_attr(not(bootstrap), rustc_nounwind)] +#[cfg_attr(bootstrap, rustc_allocator_nounwind)] fn panic_no_unwind() -> ! { - if cfg!(feature = "panic_immediate_abort") { - super::intrinsics::abort() - } - - // NOTE This function never crosses the FFI boundary; it's a Rust-to-Rust call - // that gets resolved to the `#[panic_handler]` function. - extern "Rust" { - #[lang = "panic_impl"] - fn panic_impl(pi: &PanicInfo<'_>) -> !; - } - - // PanicInfo with the `can_unwind` flag set to false forces an abort. - let fmt = format_args!("panic in a function that cannot unwind"); - let pi = PanicInfo::internal_constructor(Some(&fmt), Location::caller(), false); - - // SAFETY: `panic_impl` is defined in safe Rust code and thus is safe to call. - unsafe { panic_impl(&pi) } -} - -/// The entry point for panicking with a formatted message. -/// -/// This is designed to reduce the amount of code required at the call -/// site as much as possible (so that `panic!()` has as low an impact -/// on (e.g.) the inlining of other functions as possible), by moving -/// the actual formatting into this shared place. -#[cold] -// If panic_immediate_abort, inline the abort call, -// otherwise avoid inlining because of it is cold path. -#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))] -#[cfg_attr(feature = "panic_immediate_abort", inline)] -#[track_caller] -#[lang = "panic_fmt"] // needed for const-evaluated panics -#[rustc_do_not_const_check] // hooked by const-eval -#[rustc_const_unstable(feature = "core_panic", issue = "none")] -pub const fn panic_fmt(fmt: fmt::Arguments<'_>) -> ! { - if cfg!(feature = "panic_immediate_abort") { - super::intrinsics::abort() - } - - // NOTE This function never crosses the FFI boundary; it's a Rust-to-Rust call - // that gets resolved to the `#[panic_handler]` function. - extern "Rust" { - #[lang = "panic_impl"] - fn panic_impl(pi: &PanicInfo<'_>) -> !; - } - - let pi = PanicInfo::internal_constructor(Some(&fmt), Location::caller(), true); - - // SAFETY: `panic_impl` is defined in safe Rust code and thus is safe to call. - unsafe { panic_impl(&pi) } + panic_str_nounwind("panic in a function that cannot unwind") } /// This function is used instead of panic_fmt in const eval. @@ -190,11 +212,11 @@ pub fn assert_matches_failed<T: fmt::Debug + ?Sized>( right: &str, args: Option<fmt::Arguments<'_>>, ) -> ! { - // Use the Display implementation to display the pattern. + // The pattern is a string so it can be displayed directly. struct Pattern<'a>(&'a str); impl fmt::Debug for Pattern<'_> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - fmt::Display::fmt(self.0, f) + f.write_str(self.0) } } assert_failed_inner(AssertKind::Match, &left, &Pattern(right), args); diff --git a/library/core/src/primitive_docs.rs b/library/core/src/primitive_docs.rs index b8e546164..331714a99 100644 --- a/library/core/src/primitive_docs.rs +++ b/library/core/src/primitive_docs.rs @@ -611,7 +611,19 @@ mod prim_pointer {} /// /// Arrays coerce to [slices (`[T]`)][slice], so a slice method may be called on /// an array. Indeed, this provides most of the API for working with arrays. -/// Slices have a dynamic size and do not coerce to arrays. +/// +/// Slices have a dynamic size and do not coerce to arrays. Instead, use +/// `slice.try_into().unwrap()` or `<ArrayType>::try_from(slice).unwrap()`. +/// +/// Array's `try_from(slice)` implementations (and the corresponding `slice.try_into()` +/// array implementations) succeed if the input slice length is the same as the result +/// array length. They optimize especially well when the optimizer can easily determine +/// the slice length, e.g. `<[u8; 4]>::try_from(&slice[4..8]).unwrap()`. Array implements +/// [TryFrom](crate::convert::TryFrom) returning: +/// +/// - `[T; N]` copies from the slice's elements +/// - `&[T; N]` references the original slice's elements +/// - `&mut [T; N]` references the original slice's elements /// /// You can move elements out of an array with a [slice pattern]. If you want /// one element, see [`mem::replace`]. @@ -640,6 +652,15 @@ mod prim_pointer {} /// for x in &array { } /// ``` /// +/// You can use `<ArrayType>::try_from(slice)` or `slice.try_into()` to get an array from +/// a slice: +/// +/// ``` +/// let bytes: [u8; 3] = [1, 0, 2]; +/// assert_eq!(1, u16::from_le_bytes(<[u8; 2]>::try_from(&bytes[0..2]).unwrap())); +/// assert_eq!(512, u16::from_le_bytes(bytes[1..3].try_into().unwrap())); +/// ``` +/// /// You can use a [slice pattern] to move elements out of an array: /// /// ``` @@ -801,11 +822,53 @@ mod prim_array {} /// assert_eq!(2 * pointer_size, std::mem::size_of::<Box<[u8]>>()); /// assert_eq!(2 * pointer_size, std::mem::size_of::<Rc<[u8]>>()); /// ``` +/// +/// ## Trait Implementations +/// +/// Some traits are implemented for slices if the element type implements +/// that trait. This includes [`Eq`], [`Hash`] and [`Ord`]. +/// +/// ## Iteration +/// +/// The slices implement `IntoIterator`. The iterator yields references to the +/// slice elements. +/// +/// ``` +/// let numbers: &[i32] = &[0, 1, 2]; +/// for n in numbers { +/// println!("{n} is a number!"); +/// } +/// ``` +/// +/// The mutable slice yields mutable references to the elements: +/// +/// ``` +/// let mut scores: &mut [i32] = &mut [7, 8, 9]; +/// for score in scores { +/// *score += 1; +/// } +/// ``` +/// +/// This iterator yields mutable references to the slice's elements, so while +/// the element type of the slice is `i32`, the element type of the iterator is +/// `&mut i32`. +/// +/// * [`.iter`] and [`.iter_mut`] are the explicit methods to return the default +/// iterators. +/// * Further methods that return iterators are [`.split`], [`.splitn`], +/// [`.chunks`], [`.windows`] and more. +/// +/// [`Hash`]: core::hash::Hash +/// [`.iter`]: slice::iter +/// [`.iter_mut`]: slice::iter_mut +/// [`.split`]: slice::split +/// [`.splitn`]: slice::splitn +/// [`.chunks`]: slice::chunks +/// [`.windows`]: slice::windows #[stable(feature = "rust1", since = "1.0.0")] mod prim_slice {} #[doc(primitive = "str")] -// /// String slices. /// /// *[See also the `std::str` module](crate::str).* @@ -816,19 +879,22 @@ mod prim_slice {} /// /// String slices are always valid UTF-8. /// -/// # Examples +/// # Basic Usage /// /// String literals are string slices: /// /// ``` -/// let hello = "Hello, world!"; -/// -/// // with an explicit type annotation -/// let hello: &'static str = "Hello, world!"; +/// let hello_world = "Hello, World!"; /// ``` /// -/// They are `'static` because they're stored directly in the final binary, and -/// so will be valid for the `'static` duration. +/// Here we have declared a string slice initialized with a string literal. +/// String literals have a static lifetime, which means the string `hello_world` +/// is guaranteed to be valid for the duration of the entire program. +/// We can explicitly specify `hello_world`'s lifetime as well: +/// +/// ``` +/// let hello_world: &'static str = "Hello, world!"; +/// ``` /// /// # Representation /// @@ -996,7 +1062,7 @@ impl<T> (T,) {} // Fake impl that's only really used for docs. #[cfg(doc)] #[stable(feature = "rust1", since = "1.0.0")] -#[cfg_attr(not(bootstrap), doc(fake_variadic))] +#[doc(fake_variadic)] /// This trait is implemented on arbitrary-length tuples. impl<T: Clone> Clone for (T,) { fn clone(&self) -> Self { @@ -1007,7 +1073,7 @@ impl<T: Clone> Clone for (T,) { // Fake impl that's only really used for docs. #[cfg(doc)] #[stable(feature = "rust1", since = "1.0.0")] -#[cfg_attr(not(bootstrap), doc(fake_variadic))] +#[doc(fake_variadic)] /// This trait is implemented on arbitrary-length tuples. impl<T: Copy> Copy for (T,) { // empty @@ -1178,7 +1244,7 @@ mod prim_usize {} #[doc(alias = "&")] #[doc(alias = "&mut")] // -/// References, both shared and mutable. +/// References, `&T` and `&mut T`. /// /// A reference represents a borrow of some owned value. You can get one by using the `&` or `&mut` /// operators on a value, or by using a [`ref`](../std/keyword.ref.html) or @@ -1484,13 +1550,12 @@ mod prim_fn {} // Required to make auto trait impls render. // See src/librustdoc/passes/collect_trait_impls.rs:collect_trait_impls #[doc(hidden)] -#[cfg(not(bootstrap))] impl<Ret, T> fn(T) -> Ret {} // Fake impl that's only really used for docs. #[cfg(doc)] #[stable(feature = "rust1", since = "1.0.0")] -#[cfg_attr(not(bootstrap), doc(fake_variadic))] +#[doc(fake_variadic)] /// This trait is implemented on function pointers with any number of arguments. impl<Ret, T> Clone for fn(T) -> Ret { fn clone(&self) -> Self { @@ -1501,7 +1566,7 @@ impl<Ret, T> Clone for fn(T) -> Ret { // Fake impl that's only really used for docs. #[cfg(doc)] #[stable(feature = "rust1", since = "1.0.0")] -#[cfg_attr(not(bootstrap), doc(fake_variadic))] +#[doc(fake_variadic)] /// This trait is implemented on function pointers with any number of arguments. impl<Ret, T> Copy for fn(T) -> Ret { // empty diff --git a/library/core/src/mem/valid_align.rs b/library/core/src/ptr/alignment.rs index fcfa95120..1390e09dd 100644 --- a/library/core/src/mem/valid_align.rs +++ b/library/core/src/ptr/alignment.rs @@ -1,4 +1,5 @@ -use crate::convert::TryFrom; +use crate::convert::{TryFrom, TryInto}; +use crate::intrinsics::assert_unsafe_precondition; use crate::num::NonZeroUsize; use crate::{cmp, fmt, hash, mem, num}; @@ -7,16 +8,62 @@ use crate::{cmp, fmt, hash, mem, num}; /// /// Note that particularly large alignments, while representable in this type, /// are likely not to be supported by actual allocators and linkers. -#[derive(Copy, Clone)] +#[unstable(feature = "ptr_alignment_type", issue = "102070")] +#[derive(Copy, Clone, Eq, PartialEq)] #[repr(transparent)] -pub(crate) struct ValidAlign(ValidAlignEnum); +pub struct Alignment(AlignmentEnum); -// ValidAlign is `repr(usize)`, but via extra steps. -const _: () = assert!(mem::size_of::<ValidAlign>() == mem::size_of::<usize>()); -const _: () = assert!(mem::align_of::<ValidAlign>() == mem::align_of::<usize>()); +// Alignment is `repr(usize)`, but via extra steps. +const _: () = assert!(mem::size_of::<Alignment>() == mem::size_of::<usize>()); +const _: () = assert!(mem::align_of::<Alignment>() == mem::align_of::<usize>()); -impl ValidAlign { - /// Creates a `ValidAlign` from a power-of-two `usize`. +fn _alignment_can_be_structurally_matched(a: Alignment) -> bool { + matches!(a, Alignment::MIN) +} + +impl Alignment { + /// The smallest possible alignment, 1. + /// + /// All addresses are always aligned at least this much. + /// + /// # Examples + /// + /// ``` + /// #![feature(ptr_alignment_type)] + /// use std::ptr::Alignment; + /// + /// assert_eq!(Alignment::MIN.as_usize(), 1); + /// ``` + #[unstable(feature = "ptr_alignment_type", issue = "102070")] + pub const MIN: Self = Self(AlignmentEnum::_Align1Shl0); + + /// Returns the alignment for a type. + /// + /// This provides the same numerical value as [`mem::align_of`], + /// but in an `Alignment` instead of a `usize. + #[unstable(feature = "ptr_alignment_type", issue = "102070")] + #[inline] + pub const fn of<T>() -> Self { + // SAFETY: rustc ensures that type alignment is always a power of two. + unsafe { Alignment::new_unchecked(mem::align_of::<T>()) } + } + + /// Creates an `Alignment` from a `usize`, or returns `None` if it's + /// not a power of two. + /// + /// Note that `0` is not a power of two, nor a valid alignment. + #[unstable(feature = "ptr_alignment_type", issue = "102070")] + #[inline] + pub const fn new(align: usize) -> Option<Self> { + if align.is_power_of_two() { + // SAFETY: Just checked it only has one bit set + Some(unsafe { Self::new_unchecked(align) }) + } else { + None + } + } + + /// Creates an `Alignment` from a power-of-two `usize`. /// /// # Safety /// @@ -24,88 +71,120 @@ impl ValidAlign { /// /// Equivalently, it must be `1 << exp` for some `exp` in `0..usize::BITS`. /// It must *not* be zero. + #[unstable(feature = "ptr_alignment_type", issue = "102070")] + #[rustc_const_unstable(feature = "ptr_alignment_type", issue = "102070")] #[inline] - pub(crate) const unsafe fn new_unchecked(align: usize) -> Self { - debug_assert!(align.is_power_of_two()); + pub const unsafe fn new_unchecked(align: usize) -> Self { + // SAFETY: Precondition passed to the caller. + unsafe { + assert_unsafe_precondition!( + "Alignment::new_unchecked requires a power of two", + (align: usize) => align.is_power_of_two() + ) + }; // SAFETY: By precondition, this must be a power of two, and // our variants encompass all possible powers of two. - unsafe { mem::transmute::<usize, ValidAlign>(align) } + unsafe { mem::transmute::<usize, Alignment>(align) } + } + + /// Returns the alignment as a [`usize`] + #[unstable(feature = "ptr_alignment_type", issue = "102070")] + #[rustc_const_unstable(feature = "ptr_alignment_type", issue = "102070")] + #[inline] + pub const fn as_usize(self) -> usize { + self.0 as usize } + /// Returns the alignment as a [`NonZeroUsize`] + #[unstable(feature = "ptr_alignment_type", issue = "102070")] #[inline] - pub(crate) const fn as_nonzero(self) -> NonZeroUsize { + pub const fn as_nonzero(self) -> NonZeroUsize { // SAFETY: All the discriminants are non-zero. - unsafe { NonZeroUsize::new_unchecked(self.0 as usize) } + unsafe { NonZeroUsize::new_unchecked(self.as_usize()) } } - /// Returns the base 2 logarithm of the alignment. + /// Returns the base-2 logarithm of the alignment. /// /// This is always exact, as `self` represents a power of two. + /// + /// # Examples + /// + /// ``` + /// #![feature(ptr_alignment_type)] + /// use std::ptr::Alignment; + /// + /// assert_eq!(Alignment::of::<u8>().log2(), 0); + /// assert_eq!(Alignment::new(1024).unwrap().log2(), 10); + /// ``` + #[unstable(feature = "ptr_alignment_type", issue = "102070")] #[inline] - pub(crate) fn log2(self) -> u32 { + pub fn log2(self) -> u32 { self.as_nonzero().trailing_zeros() } } -impl fmt::Debug for ValidAlign { +#[unstable(feature = "ptr_alignment_type", issue = "102070")] +impl fmt::Debug for Alignment { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { write!(f, "{:?} (1 << {:?})", self.as_nonzero(), self.log2()) } } -impl TryFrom<NonZeroUsize> for ValidAlign { +#[unstable(feature = "ptr_alignment_type", issue = "102070")] +impl TryFrom<NonZeroUsize> for Alignment { type Error = num::TryFromIntError; #[inline] - fn try_from(align: NonZeroUsize) -> Result<ValidAlign, Self::Error> { - if align.is_power_of_two() { - // SAFETY: Just checked for power-of-two - unsafe { Ok(ValidAlign::new_unchecked(align.get())) } - } else { - Err(num::TryFromIntError(())) - } + fn try_from(align: NonZeroUsize) -> Result<Alignment, Self::Error> { + align.get().try_into() } } -impl TryFrom<usize> for ValidAlign { +#[unstable(feature = "ptr_alignment_type", issue = "102070")] +impl TryFrom<usize> for Alignment { type Error = num::TryFromIntError; #[inline] - fn try_from(align: usize) -> Result<ValidAlign, Self::Error> { - if align.is_power_of_two() { - // SAFETY: Just checked for power-of-two - unsafe { Ok(ValidAlign::new_unchecked(align)) } - } else { - Err(num::TryFromIntError(())) - } + fn try_from(align: usize) -> Result<Alignment, Self::Error> { + Self::new(align).ok_or(num::TryFromIntError(())) } } -impl cmp::Eq for ValidAlign {} +#[unstable(feature = "ptr_alignment_type", issue = "102070")] +impl From<Alignment> for NonZeroUsize { + #[inline] + fn from(align: Alignment) -> NonZeroUsize { + align.as_nonzero() + } +} -impl cmp::PartialEq for ValidAlign { +#[unstable(feature = "ptr_alignment_type", issue = "102070")] +impl From<Alignment> for usize { #[inline] - fn eq(&self, other: &Self) -> bool { - self.as_nonzero() == other.as_nonzero() + fn from(align: Alignment) -> usize { + align.as_usize() } } -impl cmp::Ord for ValidAlign { +#[unstable(feature = "ptr_alignment_type", issue = "102070")] +impl cmp::Ord for Alignment { #[inline] fn cmp(&self, other: &Self) -> cmp::Ordering { self.as_nonzero().cmp(&other.as_nonzero()) } } -impl cmp::PartialOrd for ValidAlign { +#[unstable(feature = "ptr_alignment_type", issue = "102070")] +impl cmp::PartialOrd for Alignment { #[inline] fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> { Some(self.cmp(other)) } } -impl hash::Hash for ValidAlign { +#[unstable(feature = "ptr_alignment_type", issue = "102070")] +impl hash::Hash for Alignment { #[inline] fn hash<H: hash::Hasher>(&self, state: &mut H) { self.as_nonzero().hash(state) @@ -113,15 +192,15 @@ impl hash::Hash for ValidAlign { } #[cfg(target_pointer_width = "16")] -type ValidAlignEnum = ValidAlignEnum16; +type AlignmentEnum = AlignmentEnum16; #[cfg(target_pointer_width = "32")] -type ValidAlignEnum = ValidAlignEnum32; +type AlignmentEnum = AlignmentEnum32; #[cfg(target_pointer_width = "64")] -type ValidAlignEnum = ValidAlignEnum64; +type AlignmentEnum = AlignmentEnum64; -#[derive(Copy, Clone)] +#[derive(Copy, Clone, Eq, PartialEq)] #[repr(u16)] -enum ValidAlignEnum16 { +enum AlignmentEnum16 { _Align1Shl0 = 1 << 0, _Align1Shl1 = 1 << 1, _Align1Shl2 = 1 << 2, @@ -140,9 +219,9 @@ enum ValidAlignEnum16 { _Align1Shl15 = 1 << 15, } -#[derive(Copy, Clone)] +#[derive(Copy, Clone, Eq, PartialEq)] #[repr(u32)] -enum ValidAlignEnum32 { +enum AlignmentEnum32 { _Align1Shl0 = 1 << 0, _Align1Shl1 = 1 << 1, _Align1Shl2 = 1 << 2, @@ -177,9 +256,9 @@ enum ValidAlignEnum32 { _Align1Shl31 = 1 << 31, } -#[derive(Copy, Clone)] +#[derive(Copy, Clone, Eq, PartialEq)] #[repr(u64)] -enum ValidAlignEnum64 { +enum AlignmentEnum64 { _Align1Shl0 = 1 << 0, _Align1Shl1 = 1 << 1, _Align1Shl2 = 1 << 2, diff --git a/library/core/src/ptr/const_ptr.rs b/library/core/src/ptr/const_ptr.rs index e0655d68d..5a083227b 100644 --- a/library/core/src/ptr/const_ptr.rs +++ b/library/core/src/ptr/const_ptr.rs @@ -36,7 +36,10 @@ impl<T: ?Sized> *const T { pub const fn is_null(self) -> bool { // Compare via a cast to a thin pointer, so fat pointers are only // considering their "data" part for null-ness. - (self as *const u8).guaranteed_eq(null()) + match (self as *const u8).guaranteed_eq(null()) { + None => false, + Some(res) => res, + } } /// Casts to a pointer of another type. @@ -95,8 +98,8 @@ impl<T: ?Sized> *const T { /// /// This is a bit safer than `as` because it wouldn't silently change the type if the code is /// refactored. - #[unstable(feature = "ptr_const_cast", issue = "92675")] - #[rustc_const_unstable(feature = "ptr_const_cast", issue = "92675")] + #[stable(feature = "ptr_const_cast", since = "1.65.0")] + #[rustc_const_stable(feature = "ptr_const_cast", since = "1.65.0")] pub const fn cast_mut(self) -> *mut T { self as _ } @@ -154,7 +157,7 @@ impl<T: ?Sized> *const T { /// This is similar to `self as usize`, which semantically discards *provenance* and /// *address-space* information. However, unlike `self as usize`, casting the returned address /// back to a pointer yields [`invalid`][], which is undefined behavior to dereference. To - /// properly restore the lost information and obtain a dereferencable pointer, use + /// properly restore the lost information and obtain a dereferenceable pointer, use /// [`with_addr`][pointer::with_addr] or [`map_addr`][pointer::map_addr]. /// /// If using those APIs is not possible because there is no way to preserve a pointer with the @@ -249,7 +252,7 @@ impl<T: ?Sized> *const T { let offset = dest_addr.wrapping_sub(self_addr); // This is the canonical desugarring of this operation - self.cast::<u8>().wrapping_offset(offset).cast::<T>() + self.wrapping_byte_offset(offset) } /// Creates a new pointer by mapping `self`'s address to a new one. @@ -559,6 +562,20 @@ impl<T: ?Sized> *const T { from_raw_parts::<T>(self.cast::<u8>().wrapping_offset(count).cast::<()>(), metadata(self)) } + /// Masks out bits of the pointer according to a mask. + /// + /// This is convenience for `ptr.map_addr(|a| a & mask)`. + /// + /// For non-`Sized` pointees this operation changes only the data pointer, + /// leaving the metadata untouched. + #[unstable(feature = "ptr_mask", issue = "98290")] + #[must_use = "returns a new pointer rather than modifying its argument"] + #[inline(always)] + pub fn mask(self, mask: usize) -> *const T { + let this = intrinsics::ptr_mask(self.cast::<()>(), mask); + from_raw_parts::<T>(this, metadata(self)) + } + /// Calculates the distance between two pointers. The returned value is in /// units of T: the distance in bytes divided by `mem::size_of::<T>()`. /// @@ -641,7 +658,7 @@ impl<T: ?Sized> *const T { /// } /// ``` #[stable(feature = "ptr_offset_from", since = "1.47.0")] - #[rustc_const_unstable(feature = "const_ptr_offset_from", issue = "92980")] + #[rustc_const_stable(feature = "const_ptr_offset_from", since = "1.65.0")] #[inline] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn offset_from(self, origin: *const T) -> isize @@ -677,7 +694,7 @@ impl<T: ?Sized> *const T { /// units of T: the distance in bytes is divided by `mem::size_of::<T>()`. /// /// This computes the same value that [`offset_from`](#method.offset_from) - /// would compute, but with the added precondition that that the offset is + /// would compute, but with the added precondition that the offset is /// guaranteed to be non-negative. This method is equivalent to /// `usize::from(self.offset_from(origin)).unwrap_unchecked()`, /// but it provides slightly more information to the optimizer, which can @@ -740,9 +757,15 @@ impl<T: ?Sized> *const T { where T: Sized, { + let this = self; // SAFETY: The comparison has no side-effects, and the intrinsic // does this check internally in the CTFE implementation. - unsafe { assert_unsafe_precondition!(self >= origin) }; + unsafe { + assert_unsafe_precondition!( + "ptr::sub_ptr requires `this >= origin`", + [T](this: *const T, origin: *const T) => this >= origin + ) + }; let pointee_size = mem::size_of::<T>(); assert!(0 < pointee_size && pointee_size <= isize::MAX as usize); @@ -752,20 +775,16 @@ impl<T: ?Sized> *const T { /// Returns whether two pointers are guaranteed to be equal. /// - /// At runtime this function behaves like `self == other`. + /// At runtime this function behaves like `Some(self == other)`. /// However, in some contexts (e.g., compile-time evaluation), /// it is not always possible to determine equality of two pointers, so this function may - /// spuriously return `false` for pointers that later actually turn out to be equal. - /// But when it returns `true`, the pointers are guaranteed to be equal. + /// spuriously return `None` for pointers that later actually turn out to have its equality known. + /// But when it returns `Some`, the pointers' equality is guaranteed to be known. /// - /// This function is the mirror of [`guaranteed_ne`], but not its inverse. There are pointer - /// comparisons for which both functions return `false`. - /// - /// [`guaranteed_ne`]: #method.guaranteed_ne - /// - /// The return value may change depending on the compiler version and unsafe code must not + /// The return value may change from `Some` to `None` and vice versa depending on the compiler + /// version and unsafe code must not /// rely on the result of this function for soundness. It is suggested to only use this function - /// for performance optimizations where spurious `false` return values by this function do not + /// for performance optimizations where spurious `None` return values by this function do not /// affect the outcome, but just the performance. /// The consequences of using this method to make runtime and compile-time code behave /// differently have not been explored. This method should not be used to introduce such @@ -774,29 +793,28 @@ impl<T: ?Sized> *const T { #[unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[inline] - pub const fn guaranteed_eq(self, other: *const T) -> bool + pub const fn guaranteed_eq(self, other: *const T) -> Option<bool> where T: Sized, { - intrinsics::ptr_guaranteed_eq(self, other) + match intrinsics::ptr_guaranteed_cmp(self as _, other as _) { + 2 => None, + other => Some(other == 1), + } } - /// Returns whether two pointers are guaranteed to be unequal. + /// Returns whether two pointers are guaranteed to be inequal. /// - /// At runtime this function behaves like `self != other`. + /// At runtime this function behaves like `Some(self != other)`. /// However, in some contexts (e.g., compile-time evaluation), - /// it is not always possible to determine the inequality of two pointers, so this function may - /// spuriously return `false` for pointers that later actually turn out to be unequal. - /// But when it returns `true`, the pointers are guaranteed to be unequal. - /// - /// This function is the mirror of [`guaranteed_eq`], but not its inverse. There are pointer - /// comparisons for which both functions return `false`. - /// - /// [`guaranteed_eq`]: #method.guaranteed_eq + /// it is not always possible to determine inequality of two pointers, so this function may + /// spuriously return `None` for pointers that later actually turn out to have its inequality known. + /// But when it returns `Some`, the pointers' inequality is guaranteed to be known. /// - /// The return value may change depending on the compiler version and unsafe code must not + /// The return value may change from `Some` to `None` and vice versa depending on the compiler + /// version and unsafe code must not /// rely on the result of this function for soundness. It is suggested to only use this function - /// for performance optimizations where spurious `false` return values by this function do not + /// for performance optimizations where spurious `None` return values by this function do not /// affect the outcome, but just the performance. /// The consequences of using this method to make runtime and compile-time code behave /// differently have not been explored. This method should not be used to introduce such @@ -805,11 +823,14 @@ impl<T: ?Sized> *const T { #[unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[inline] - pub const fn guaranteed_ne(self, other: *const T) -> bool + pub const fn guaranteed_ne(self, other: *const T) -> Option<bool> where T: Sized, { - intrinsics::ptr_guaranteed_ne(self, other) + match self.guaranteed_eq(other) { + None => None, + Some(eq) => Some(!eq), + } } /// Calculates the offset from a pointer (convenience for `.offset(count as isize)`). @@ -1267,20 +1288,21 @@ impl<T: ?Sized> *const T { /// Accessing adjacent `u8` as `u16` /// /// ``` - /// # fn foo(n: usize) { - /// # use std::mem::align_of; + /// use std::mem::align_of; + /// /// # unsafe { - /// let x = [5u8, 6u8, 7u8, 8u8, 9u8]; - /// let ptr = x.as_ptr().add(n) as *const u8; + /// let x = [5_u8, 6, 7, 8, 9]; + /// let ptr = x.as_ptr(); /// let offset = ptr.align_offset(align_of::<u16>()); - /// if offset < x.len() - n - 1 { - /// let u16_ptr = ptr.add(offset) as *const u16; - /// assert_ne!(*u16_ptr, 500); + /// + /// if offset < x.len() - 1 { + /// let u16_ptr = ptr.add(offset).cast::<u16>(); + /// assert!(*u16_ptr == u16::from_ne_bytes([5, 6]) || *u16_ptr == u16::from_ne_bytes([6, 7])); /// } else { /// // while the pointer can be aligned via `offset`, it would point /// // outside the allocation /// } - /// # } } + /// # } /// ``` #[stable(feature = "align_offset", since = "1.36.0")] #[rustc_const_unstable(feature = "const_align_offset", issue = "90962")] @@ -1336,11 +1358,8 @@ impl<T: ?Sized> *const T { panic!("is_aligned_to: align is not a power-of-two"); } - // SAFETY: `is_power_of_two()` will return `false` for zero. - unsafe { core::intrinsics::assume(align != 0) }; - // Cast is needed for `T: !Sized` - self.cast::<u8>().addr() % align == 0 + self.cast::<u8>().addr() & align - 1 == 0 } } diff --git a/library/core/src/ptr/metadata.rs b/library/core/src/ptr/metadata.rs index cd5edee04..caa10f181 100644 --- a/library/core/src/ptr/metadata.rs +++ b/library/core/src/ptr/metadata.rs @@ -135,16 +135,16 @@ pub const fn from_raw_parts_mut<T: ?Sized>( } #[repr(C)] -pub(crate) union PtrRepr<T: ?Sized> { - pub(crate) const_ptr: *const T, - pub(crate) mut_ptr: *mut T, - pub(crate) components: PtrComponents<T>, +union PtrRepr<T: ?Sized> { + const_ptr: *const T, + mut_ptr: *mut T, + components: PtrComponents<T>, } #[repr(C)] -pub(crate) struct PtrComponents<T: ?Sized> { - pub(crate) data_address: *const (), - pub(crate) metadata: <T as Pointee>::Metadata, +struct PtrComponents<T: ?Sized> { + data_address: *const (), + metadata: <T as Pointee>::Metadata, } // Manual impl needed to avoid `T: Copy` bound. @@ -180,7 +180,6 @@ pub struct DynMetadata<Dyn: ?Sized> { phantom: crate::marker::PhantomData<Dyn>, } -#[cfg(not(bootstrap))] extern "C" { /// Opaque type for accessing vtables. /// @@ -189,17 +188,6 @@ extern "C" { type VTable; } -/// The common prefix of all vtables. It is followed by function pointers for trait methods. -/// -/// Private implementation detail of `DynMetadata::size_of` etc. -#[repr(C)] -#[cfg(bootstrap)] -struct VTable { - drop_in_place: fn(*mut ()), - size_of: usize, - align_of: usize, -} - impl<Dyn: ?Sized> DynMetadata<Dyn> { /// Returns the size of the type associated with this vtable. #[inline] @@ -207,9 +195,6 @@ impl<Dyn: ?Sized> DynMetadata<Dyn> { // Note that "size stored in vtable" is *not* the same as "result of size_of_val_raw". // Consider a reference like `&(i32, dyn Send)`: the vtable will only store the size of the // `Send` part! - #[cfg(bootstrap)] - return self.vtable_ptr.size_of; - #[cfg(not(bootstrap))] // SAFETY: DynMetadata always contains a valid vtable pointer return unsafe { crate::intrinsics::vtable_size(self.vtable_ptr as *const VTable as *const ()) @@ -219,9 +204,6 @@ impl<Dyn: ?Sized> DynMetadata<Dyn> { /// Returns the alignment of the type associated with this vtable. #[inline] pub fn align_of(self) -> usize { - #[cfg(bootstrap)] - return self.vtable_ptr.align_of; - #[cfg(not(bootstrap))] // SAFETY: DynMetadata always contains a valid vtable pointer return unsafe { crate::intrinsics::vtable_align(self.vtable_ptr as *const VTable as *const ()) diff --git a/library/core/src/ptr/mod.rs b/library/core/src/ptr/mod.rs index 40e28e636..565c38d22 100644 --- a/library/core/src/ptr/mod.rs +++ b/library/core/src/ptr/mod.rs @@ -90,7 +90,7 @@ //! isn't *pointer*-sized but address-space/offset/allocation-sized (we'll probably continue //! to conflate these notions). This would potentially make it possible to more efficiently //! target platforms where pointers are larger than offsets, such as CHERI and maybe some -//! segmented architecures. +//! segmented architectures. //! //! ## Provenance //! @@ -172,7 +172,7 @@ //! a pointer to a usize is generally an operation which *only* extracts the address. It is //! therefore *impossible* to construct a valid pointer from a usize because there is no way //! to restore the address-space and provenance. In other words, pointer-integer-pointer -//! roundtrips are not possible (in the sense that the resulting pointer is not dereferencable). +//! roundtrips are not possible (in the sense that the resulting pointer is not dereferenceable). //! //! The key insight to making this model *at all* viable is the [`with_addr`][] method: //! @@ -272,7 +272,7 @@ //! //! * Create an invalid pointer from just an address (see [`ptr::invalid`][]). This can //! be used for sentinel values like `null` *or* to represent a tagged pointer that will -//! never be dereferencable. In general, it is always sound for an integer to pretend +//! never be dereferenceable. In general, it is always sound for an integer to pretend //! to be a pointer "for fun" as long as you don't use operations on it which require //! it to be valid (offset, read, write, etc). //! @@ -377,6 +377,10 @@ use crate::intrinsics::{ use crate::mem::{self, MaybeUninit}; +mod alignment; +#[unstable(feature = "ptr_alignment_type", issue = "102070")] +pub use alignment::Alignment; + #[stable(feature = "rust1", since = "1.0.0")] #[doc(inline)] pub use crate::intrinsics::copy_nonoverlapping; @@ -390,7 +394,6 @@ pub use crate::intrinsics::copy; pub use crate::intrinsics::write_bytes; mod metadata; -pub(crate) use metadata::PtrRepr; #[unstable(feature = "ptr_metadata", issue = "81513")] pub use metadata::{from_raw_parts, from_raw_parts_mut, metadata, DynMetadata, Pointee, Thin}; @@ -578,12 +581,21 @@ pub const fn invalid_mut<T>(addr: usize) -> *mut T { /// Convert an address back to a pointer, picking up a previously 'exposed' provenance. /// /// This is equivalent to `addr as *const T`. The provenance of the returned pointer is that of *any* -/// pointer that was previously passed to [`expose_addr`][pointer::expose_addr] or a `ptr as usize` -/// cast. If there is no previously 'exposed' provenance that justifies the way this pointer will be -/// used, the program has undefined behavior. Note that there is no algorithm that decides which -/// provenance will be used. You can think of this as "guessing" the right provenance, and the guess -/// will be "maximally in your favor", in the sense that if there is any way to avoid undefined -/// behavior, then that is the guess that will be taken. +/// pointer that was previously exposed by passing it to [`expose_addr`][pointer::expose_addr], +/// or a `ptr as usize` cast. In addition, memory which is outside the control of the Rust abstract +/// machine (MMIO registers, for example) is always considered to be exposed, so long as this memory +/// is disjoint from memory that will be used by the abstract machine such as the stack, heap, +/// and statics. +/// +/// If there is no 'exposed' provenance that justifies the way this pointer will be used, +/// the program has undefined behavior. In particular, the aliasing rules still apply: pointers +/// and references that have been invalidated due to aliasing accesses cannot be used any more, +/// even if they have been exposed! +/// +/// Note that there is no algorithm that decides which provenance will be used. You can think of this +/// as "guessing" the right provenance, and the guess will be "maximally in your favor", in the sense +/// that if there is any way to avoid undefined behavior (while upholding all aliasing requirements), +/// then that is the guess that will be taken. /// /// On platforms with multiple address spaces, it is your responsibility to ensure that the /// address makes sense in the address space that this pointer will be used with. @@ -603,6 +615,7 @@ pub const fn invalid_mut<T>(addr: usize) -> *mut T { #[must_use] #[inline] #[unstable(feature = "strict_provenance", issue = "95228")] +#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub fn from_exposed_addr<T>(addr: usize) -> *const T where T: Sized, @@ -639,6 +652,7 @@ where #[must_use] #[inline] #[unstable(feature = "strict_provenance", issue = "95228")] +#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub fn from_exposed_addr_mut<T>(addr: usize) -> *mut T where T: Sized, @@ -885,6 +899,9 @@ pub const unsafe fn swap_nonoverlapping<T>(x: *mut T, y: *mut T, count: usize) { // valid for writes and properly aligned. unsafe { assert_unsafe_precondition!( + "ptr::swap_nonoverlapping requires that both pointer arguments are aligned and non-null \ + and the specified memory ranges do not overlap", + [T](x: *mut T, y: *mut T, count: usize) => is_aligned_and_not_null(x) && is_aligned_and_not_null(y) && is_nonoverlapping(x, y, count) @@ -981,7 +998,10 @@ pub const unsafe fn replace<T>(dst: *mut T, mut src: T) -> T { // and cannot overlap `src` since `dst` must point to a distinct // allocated object. unsafe { - assert_unsafe_precondition!(is_aligned_and_not_null(dst)); + assert_unsafe_precondition!( + "ptr::replace requires that the pointer argument is aligned and non-null", + [T](dst: *mut T) => is_aligned_and_not_null(dst) + ); mem::swap(&mut *dst, &mut src); // cannot overlap } src @@ -1112,6 +1132,10 @@ pub const unsafe fn read<T>(src: *const T) -> T { // Also, since we just wrote a valid value into `tmp`, it is guaranteed // to be properly initialized. unsafe { + assert_unsafe_precondition!( + "ptr::read requires that the pointer argument is aligned and non-null", + [T](src: *const T) => is_aligned_and_not_null(src) + ); copy_nonoverlapping(src, tmp.as_mut_ptr(), 1); tmp.assume_init() } @@ -1305,6 +1329,10 @@ pub const unsafe fn write<T>(dst: *mut T, src: T) { // `dst` cannot overlap `src` because the caller has mutable access // to `dst` while `src` is owned by this function. unsafe { + assert_unsafe_precondition!( + "ptr::write requires that the pointer argument is aligned and non-null", + [T](dst: *mut T) => is_aligned_and_not_null(dst) + ); copy_nonoverlapping(&src as *const T, dst, 1); intrinsics::forget(src); } @@ -1468,7 +1496,10 @@ pub const unsafe fn write_unaligned<T>(dst: *mut T, src: T) { pub unsafe fn read_volatile<T>(src: *const T) -> T { // SAFETY: the caller must uphold the safety contract for `volatile_load`. unsafe { - assert_unsafe_precondition!(is_aligned_and_not_null(src)); + assert_unsafe_precondition!( + "ptr::read_volatile requires that the pointer argument is aligned and non-null", + [T](src: *const T) => is_aligned_and_not_null(src) + ); intrinsics::volatile_load(src) } } @@ -1539,7 +1570,10 @@ pub unsafe fn read_volatile<T>(src: *const T) -> T { pub unsafe fn write_volatile<T>(dst: *mut T, src: T) { // SAFETY: the caller must uphold the safety contract for `volatile_store`. unsafe { - assert_unsafe_precondition!(is_aligned_and_not_null(dst)); + assert_unsafe_precondition!( + "ptr::write_volatile requires that the pointer argument is aligned and non-null", + [T](dst: *mut T) => is_aligned_and_not_null(dst) + ); intrinsics::volatile_store(dst, src); } } @@ -1726,6 +1760,12 @@ pub(crate) unsafe fn align_offset<T: Sized>(p: *const T, a: usize) -> usize { /// by their address rather than comparing the values they point to /// (which is what the `PartialEq for &T` implementation does). /// +/// When comparing wide pointers, both the address and the metadata are tested for equality. +/// However, note that comparing trait object pointers (`*const dyn Trait`) is unrealiable: pointers +/// to values of the same underlying type can compare inequal (because vtables are duplicated in +/// multiple codegen units), and pointers to values of *different* underlying type can compare equal +/// (since identical vtables can be deduplicated within a codegen unit). +/// /// # Examples /// /// ``` @@ -1752,41 +1792,6 @@ pub(crate) unsafe fn align_offset<T: Sized>(p: *const T, a: usize) -> usize { /// assert!(!std::ptr::eq(&a[..2], &a[..3])); /// assert!(!std::ptr::eq(&a[0..2], &a[1..3])); /// ``` -/// -/// Traits are also compared by their implementation: -/// -/// ``` -/// #[repr(transparent)] -/// struct Wrapper { member: i32 } -/// -/// trait Trait {} -/// impl Trait for Wrapper {} -/// impl Trait for i32 {} -/// -/// let wrapper = Wrapper { member: 10 }; -/// -/// // Pointers have equal addresses. -/// assert!(std::ptr::eq( -/// &wrapper as *const Wrapper as *const u8, -/// &wrapper.member as *const i32 as *const u8 -/// )); -/// -/// // Objects have equal addresses, but `Trait` has different implementations. -/// assert!(!std::ptr::eq( -/// &wrapper as &dyn Trait, -/// &wrapper.member as &dyn Trait, -/// )); -/// assert!(!std::ptr::eq( -/// &wrapper as &dyn Trait as *const dyn Trait, -/// &wrapper.member as &dyn Trait as *const dyn Trait, -/// )); -/// -/// // Converting the reference to a `*const u8` compares by address. -/// assert!(std::ptr::eq( -/// &wrapper as &dyn Trait as *const dyn Trait as *const u8, -/// &wrapper.member as &dyn Trait as *const dyn Trait as *const u8, -/// )); -/// ``` #[stable(feature = "ptr_eq", since = "1.17.0")] #[inline] pub fn eq<T: ?Sized>(a: *const T, b: *const T) -> bool { @@ -1834,7 +1839,7 @@ macro_rules! maybe_fnptr_doc { $item }; ($a:ident @ #[$meta:meta] $item:item) => { - #[cfg_attr(not(bootstrap), doc(fake_variadic))] + #[doc(fake_variadic)] #[doc = "This trait is implemented for function pointers with up to twelve arguments."] #[$meta] $item @@ -1854,9 +1859,16 @@ macro_rules! maybe_fnptr_doc { // Impls for function pointers macro_rules! fnptr_impls_safety_abi { ($FnTy: ty, $($Arg: ident),*) => { + fnptr_impls_safety_abi! { #[stable(feature = "fnptr_impls", since = "1.4.0")] $FnTy, $($Arg),* } + }; + (@c_unwind $FnTy: ty, $($Arg: ident),*) => { + #[cfg(not(bootstrap))] + fnptr_impls_safety_abi! { #[unstable(feature = "c_unwind", issue = "74990")] $FnTy, $($Arg),* } + }; + (#[$meta:meta] $FnTy: ty, $($Arg: ident),*) => { maybe_fnptr_doc! { $($Arg)* @ - #[stable(feature = "fnptr_impls", since = "1.4.0")] + #[$meta] impl<Ret, $($Arg),*> PartialEq for $FnTy { #[inline] fn eq(&self, other: &Self) -> bool { @@ -1867,13 +1879,13 @@ macro_rules! fnptr_impls_safety_abi { maybe_fnptr_doc! { $($Arg)* @ - #[stable(feature = "fnptr_impls", since = "1.4.0")] + #[$meta] impl<Ret, $($Arg),*> Eq for $FnTy {} } maybe_fnptr_doc! { $($Arg)* @ - #[stable(feature = "fnptr_impls", since = "1.4.0")] + #[$meta] impl<Ret, $($Arg),*> PartialOrd for $FnTy { #[inline] fn partial_cmp(&self, other: &Self) -> Option<Ordering> { @@ -1884,7 +1896,7 @@ macro_rules! fnptr_impls_safety_abi { maybe_fnptr_doc! { $($Arg)* @ - #[stable(feature = "fnptr_impls", since = "1.4.0")] + #[$meta] impl<Ret, $($Arg),*> Ord for $FnTy { #[inline] fn cmp(&self, other: &Self) -> Ordering { @@ -1895,7 +1907,7 @@ macro_rules! fnptr_impls_safety_abi { maybe_fnptr_doc! { $($Arg)* @ - #[stable(feature = "fnptr_impls", since = "1.4.0")] + #[$meta] impl<Ret, $($Arg),*> hash::Hash for $FnTy { fn hash<HH: hash::Hasher>(&self, state: &mut HH) { state.write_usize(*self as usize) @@ -1905,7 +1917,7 @@ macro_rules! fnptr_impls_safety_abi { maybe_fnptr_doc! { $($Arg)* @ - #[stable(feature = "fnptr_impls", since = "1.4.0")] + #[$meta] impl<Ret, $($Arg),*> fmt::Pointer for $FnTy { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { fmt::pointer_fmt_inner(*self as usize, f) @@ -1915,7 +1927,7 @@ macro_rules! fnptr_impls_safety_abi { maybe_fnptr_doc! { $($Arg)* @ - #[stable(feature = "fnptr_impls", since = "1.4.0")] + #[$meta] impl<Ret, $($Arg),*> fmt::Debug for $FnTy { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { fmt::pointer_fmt_inner(*self as usize, f) @@ -1930,16 +1942,22 @@ macro_rules! fnptr_impls_args { fnptr_impls_safety_abi! { extern "Rust" fn($($Arg),+) -> Ret, $($Arg),+ } fnptr_impls_safety_abi! { extern "C" fn($($Arg),+) -> Ret, $($Arg),+ } fnptr_impls_safety_abi! { extern "C" fn($($Arg),+ , ...) -> Ret, $($Arg),+ } + fnptr_impls_safety_abi! { @c_unwind extern "C-unwind" fn($($Arg),+) -> Ret, $($Arg),+ } + fnptr_impls_safety_abi! { @c_unwind extern "C-unwind" fn($($Arg),+ , ...) -> Ret, $($Arg),+ } fnptr_impls_safety_abi! { unsafe extern "Rust" fn($($Arg),+) -> Ret, $($Arg),+ } fnptr_impls_safety_abi! { unsafe extern "C" fn($($Arg),+) -> Ret, $($Arg),+ } fnptr_impls_safety_abi! { unsafe extern "C" fn($($Arg),+ , ...) -> Ret, $($Arg),+ } + fnptr_impls_safety_abi! { @c_unwind unsafe extern "C-unwind" fn($($Arg),+) -> Ret, $($Arg),+ } + fnptr_impls_safety_abi! { @c_unwind unsafe extern "C-unwind" fn($($Arg),+ , ...) -> Ret, $($Arg),+ } }; () => { // No variadic functions with 0 parameters fnptr_impls_safety_abi! { extern "Rust" fn() -> Ret, } fnptr_impls_safety_abi! { extern "C" fn() -> Ret, } + fnptr_impls_safety_abi! { @c_unwind extern "C-unwind" fn() -> Ret, } fnptr_impls_safety_abi! { unsafe extern "Rust" fn() -> Ret, } fnptr_impls_safety_abi! { unsafe extern "C" fn() -> Ret, } + fnptr_impls_safety_abi! { @c_unwind unsafe extern "C-unwind" fn() -> Ret, } }; } diff --git a/library/core/src/ptr/mut_ptr.rs b/library/core/src/ptr/mut_ptr.rs index fc3dd2a9b..6764002bc 100644 --- a/library/core/src/ptr/mut_ptr.rs +++ b/library/core/src/ptr/mut_ptr.rs @@ -35,7 +35,10 @@ impl<T: ?Sized> *mut T { pub const fn is_null(self) -> bool { // Compare via a cast to a thin pointer, so fat pointers are only // considering their "data" part for null-ness. - (self as *mut u8).guaranteed_eq(null_mut()) + match (self as *mut u8).guaranteed_eq(null_mut()) { + None => false, + Some(res) => res, + } } /// Casts to a pointer of another type. @@ -77,10 +80,14 @@ impl<T: ?Sized> *mut T { #[unstable(feature = "set_ptr_value", issue = "75091")] #[must_use = "returns a new pointer rather than modifying its argument"] #[inline] - pub fn with_metadata_of<U>(self, mut val: *mut U) -> *mut U + pub fn with_metadata_of<U>(self, val: *const U) -> *mut U where U: ?Sized, { + // Prepare in the type system that we will replace the pointer value with a mutable + // pointer, taking the mutable provenance from the `self` pointer. + let mut val = val as *mut U; + // Pointer to the pointer value within the value. let target = &mut val as *mut *mut U as *mut *mut u8; // SAFETY: In case of a thin pointer, this operations is identical // to a simple assignment. In case of a fat pointer, with the current @@ -100,8 +107,8 @@ impl<T: ?Sized> *mut T { /// coercion. /// /// [`cast_mut`]: #method.cast_mut - #[unstable(feature = "ptr_const_cast", issue = "92675")] - #[rustc_const_unstable(feature = "ptr_const_cast", issue = "92675")] + #[stable(feature = "ptr_const_cast", since = "1.65.0")] + #[rustc_const_stable(feature = "ptr_const_cast", since = "1.65.0")] pub const fn cast_const(self) -> *const T { self as _ } @@ -160,7 +167,7 @@ impl<T: ?Sized> *mut T { /// This is similar to `self as usize`, which semantically discards *provenance* and /// *address-space* information. However, unlike `self as usize`, casting the returned address /// back to a pointer yields [`invalid`][], which is undefined behavior to dereference. To - /// properly restore the lost information and obtain a dereferencable pointer, use + /// properly restore the lost information and obtain a dereferenceable pointer, use /// [`with_addr`][pointer::with_addr] or [`map_addr`][pointer::map_addr]. /// /// If using those APIs is not possible because there is no way to preserve a pointer with the @@ -255,7 +262,7 @@ impl<T: ?Sized> *mut T { let offset = dest_addr.wrapping_sub(self_addr); // This is the canonical desugarring of this operation - self.cast::<u8>().wrapping_offset(offset).cast::<T>() + self.wrapping_byte_offset(offset) } /// Creates a new pointer by mapping `self`'s address to a new one. @@ -575,6 +582,20 @@ impl<T: ?Sized> *mut T { ) } + /// Masks out bits of the pointer according to a mask. + /// + /// This is convenience for `ptr.map_addr(|a| a & mask)`. + /// + /// For non-`Sized` pointees this operation changes only the data pointer, + /// leaving the metadata untouched. + #[unstable(feature = "ptr_mask", issue = "98290")] + #[must_use = "returns a new pointer rather than modifying its argument"] + #[inline(always)] + pub fn mask(self, mask: usize) -> *mut T { + let this = intrinsics::ptr_mask(self.cast::<()>(), mask) as *mut (); + from_raw_parts_mut::<T>(this, metadata(self)) + } + /// Returns `None` if the pointer is null, or else returns a unique reference to /// the value wrapped in `Some`. If the value may be uninitialized, [`as_uninit_mut`] /// must be used instead. @@ -682,20 +703,16 @@ impl<T: ?Sized> *mut T { /// Returns whether two pointers are guaranteed to be equal. /// - /// At runtime this function behaves like `self == other`. + /// At runtime this function behaves like `Some(self == other)`. /// However, in some contexts (e.g., compile-time evaluation), /// it is not always possible to determine equality of two pointers, so this function may - /// spuriously return `false` for pointers that later actually turn out to be equal. - /// But when it returns `true`, the pointers are guaranteed to be equal. + /// spuriously return `None` for pointers that later actually turn out to have its equality known. + /// But when it returns `Some`, the pointers' equality is guaranteed to be known. /// - /// This function is the mirror of [`guaranteed_ne`], but not its inverse. There are pointer - /// comparisons for which both functions return `false`. - /// - /// [`guaranteed_ne`]: #method.guaranteed_ne - /// - /// The return value may change depending on the compiler version and unsafe code might not + /// The return value may change from `Some` to `None` and vice versa depending on the compiler + /// version and unsafe code must not /// rely on the result of this function for soundness. It is suggested to only use this function - /// for performance optimizations where spurious `false` return values by this function do not + /// for performance optimizations where spurious `None` return values by this function do not /// affect the outcome, but just the performance. /// The consequences of using this method to make runtime and compile-time code behave /// differently have not been explored. This method should not be used to introduce such @@ -704,29 +721,25 @@ impl<T: ?Sized> *mut T { #[unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[inline] - pub const fn guaranteed_eq(self, other: *mut T) -> bool + pub const fn guaranteed_eq(self, other: *mut T) -> Option<bool> where T: Sized, { - intrinsics::ptr_guaranteed_eq(self as *const _, other as *const _) + (self as *const T).guaranteed_eq(other as _) } - /// Returns whether two pointers are guaranteed to be unequal. + /// Returns whether two pointers are guaranteed to be inequal. /// - /// At runtime this function behaves like `self != other`. + /// At runtime this function behaves like `Some(self != other)`. /// However, in some contexts (e.g., compile-time evaluation), - /// it is not always possible to determine the inequality of two pointers, so this function may - /// spuriously return `false` for pointers that later actually turn out to be unequal. - /// But when it returns `true`, the pointers are guaranteed to be unequal. - /// - /// This function is the mirror of [`guaranteed_eq`], but not its inverse. There are pointer - /// comparisons for which both functions return `false`. + /// it is not always possible to determine inequality of two pointers, so this function may + /// spuriously return `None` for pointers that later actually turn out to have its inequality known. + /// But when it returns `Some`, the pointers' inequality is guaranteed to be known. /// - /// [`guaranteed_eq`]: #method.guaranteed_eq - /// - /// The return value may change depending on the compiler version and unsafe code might not + /// The return value may change from `Some` to `None` and vice versa depending on the compiler + /// version and unsafe code must not /// rely on the result of this function for soundness. It is suggested to only use this function - /// for performance optimizations where spurious `false` return values by this function do not + /// for performance optimizations where spurious `None` return values by this function do not /// affect the outcome, but just the performance. /// The consequences of using this method to make runtime and compile-time code behave /// differently have not been explored. This method should not be used to introduce such @@ -735,11 +748,11 @@ impl<T: ?Sized> *mut T { #[unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[rustc_const_unstable(feature = "const_raw_ptr_comparison", issue = "53020")] #[inline] - pub const unsafe fn guaranteed_ne(self, other: *mut T) -> bool + pub const fn guaranteed_ne(self, other: *mut T) -> Option<bool> where T: Sized, { - intrinsics::ptr_guaranteed_ne(self as *const _, other as *const _) + (self as *const T).guaranteed_ne(other as _) } /// Calculates the distance between two pointers. The returned value is in @@ -824,7 +837,7 @@ impl<T: ?Sized> *mut T { /// } /// ``` #[stable(feature = "ptr_offset_from", since = "1.47.0")] - #[rustc_const_unstable(feature = "const_ptr_offset_from", issue = "92980")] + #[rustc_const_stable(feature = "const_ptr_offset_from", since = "1.65.0")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn offset_from(self, origin: *const T) -> isize @@ -858,7 +871,7 @@ impl<T: ?Sized> *mut T { /// units of T: the distance in bytes is divided by `mem::size_of::<T>()`. /// /// This computes the same value that [`offset_from`](#method.offset_from) - /// would compute, but with the added precondition that that the offset is + /// would compute, but with the added precondition that the offset is /// guaranteed to be non-negative. This method is equivalent to /// `usize::from(self.offset_from(origin)).unwrap_unchecked()`, /// but it provides slightly more information to the optimizer, which can @@ -1545,20 +1558,23 @@ impl<T: ?Sized> *mut T { /// Accessing adjacent `u8` as `u16` /// /// ``` - /// # fn foo(n: usize) { - /// # use std::mem::align_of; + /// use std::mem::align_of; + /// /// # unsafe { - /// let x = [5u8, 6u8, 7u8, 8u8, 9u8]; - /// let ptr = x.as_ptr().add(n) as *const u8; + /// let mut x = [5_u8, 6, 7, 8, 9]; + /// let ptr = x.as_mut_ptr(); /// let offset = ptr.align_offset(align_of::<u16>()); - /// if offset < x.len() - n - 1 { - /// let u16_ptr = ptr.add(offset) as *const u16; - /// assert_ne!(*u16_ptr, 500); + /// + /// if offset < x.len() - 1 { + /// let u16_ptr = ptr.add(offset).cast::<u16>(); + /// *u16_ptr = 0; + /// + /// assert!(x == [0, 0, 7, 8, 9] || x == [5, 0, 0, 8, 9]); /// } else { /// // while the pointer can be aligned via `offset`, it would point /// // outside the allocation /// } - /// # } } + /// # } /// ``` #[stable(feature = "align_offset", since = "1.36.0")] #[rustc_const_unstable(feature = "const_align_offset", issue = "90962")] @@ -1614,11 +1630,8 @@ impl<T: ?Sized> *mut T { panic!("is_aligned_to: align is not a power-of-two"); } - // SAFETY: `is_power_of_two()` will return `false` for zero. - unsafe { core::intrinsics::assume(align != 0) }; - // Cast is needed for `T: !Sized` - self.cast::<u8>().addr() % align == 0 + self.cast::<u8>().addr() & align - 1 == 0 } } diff --git a/library/core/src/ptr/non_null.rs b/library/core/src/ptr/non_null.rs index f3ef094cb..c18264d13 100644 --- a/library/core/src/ptr/non_null.rs +++ b/library/core/src/ptr/non_null.rs @@ -2,6 +2,7 @@ use crate::cmp::Ordering; use crate::convert::From; use crate::fmt; use crate::hash; +use crate::intrinsics::assert_unsafe_precondition; use crate::marker::Unsize; use crate::mem::{self, MaybeUninit}; use crate::num::NonZeroUsize; @@ -195,7 +196,10 @@ impl<T: ?Sized> NonNull<T> { #[inline] pub const unsafe fn new_unchecked(ptr: *mut T) -> Self { // SAFETY: the caller must guarantee that `ptr` is non-null. - unsafe { NonNull { pointer: ptr as _ } } + unsafe { + assert_unsafe_precondition!("NonNull::new_unchecked requires that the pointer is non-null", [T: ?Sized](ptr: *mut T) => !ptr.is_null()); + NonNull { pointer: ptr as _ } + } } /// Creates a new `NonNull` if `ptr` is non-null. diff --git a/library/core/src/result.rs b/library/core/src/result.rs index 45b052c82..3f33c5fd6 100644 --- a/library/core/src/result.rs +++ b/library/core/src/result.rs @@ -548,22 +548,25 @@ impl<T, E> Result<T, E> { /// # Examples /// /// ``` - /// #![feature(is_some_with)] + /// #![feature(is_some_and)] /// /// let x: Result<u32, &str> = Ok(2); - /// assert_eq!(x.is_ok_and(|&x| x > 1), true); + /// assert_eq!(x.is_ok_and(|x| x > 1), true); /// /// let x: Result<u32, &str> = Ok(0); - /// assert_eq!(x.is_ok_and(|&x| x > 1), false); + /// assert_eq!(x.is_ok_and(|x| x > 1), false); /// /// let x: Result<u32, &str> = Err("hey"); - /// assert_eq!(x.is_ok_and(|&x| x > 1), false); + /// assert_eq!(x.is_ok_and(|x| x > 1), false); /// ``` #[must_use] #[inline] - #[unstable(feature = "is_some_with", issue = "93050")] - pub fn is_ok_and(&self, f: impl FnOnce(&T) -> bool) -> bool { - matches!(self, Ok(x) if f(x)) + #[unstable(feature = "is_some_and", issue = "93050")] + pub fn is_ok_and(self, f: impl FnOnce(T) -> bool) -> bool { + match self { + Err(_) => false, + Ok(x) => f(x), + } } /// Returns `true` if the result is [`Err`]. @@ -592,7 +595,7 @@ impl<T, E> Result<T, E> { /// # Examples /// /// ``` - /// #![feature(is_some_with)] + /// #![feature(is_some_and)] /// use std::io::{Error, ErrorKind}; /// /// let x: Result<u32, Error> = Err(Error::new(ErrorKind::NotFound, "!")); @@ -606,9 +609,12 @@ impl<T, E> Result<T, E> { /// ``` #[must_use] #[inline] - #[unstable(feature = "is_some_with", issue = "93050")] - pub fn is_err_and(&self, f: impl FnOnce(&E) -> bool) -> bool { - matches!(self, Err(x) if f(x)) + #[unstable(feature = "is_some_and", issue = "93050")] + pub fn is_err_and(self, f: impl FnOnce(E) -> bool) -> bool { + match self { + Ok(_) => false, + Err(e) => f(e), + } } ///////////////////////////////////////////////////////////////////////// @@ -1285,6 +1291,11 @@ impl<T, E> Result<T, E> { /// Returns `res` if the result is [`Ok`], otherwise returns the [`Err`] value of `self`. /// + /// Arguments passed to `and` are eagerly evaluated; if you are passing the + /// result of a function call, it is recommended to use [`and_then`], which is + /// lazily evaluated. + /// + /// [`and_then`]: Result::and_then /// /// # Examples /// @@ -1771,40 +1782,6 @@ impl<T, E> Result<Result<T, E>, E> { } } -impl<T> Result<T, T> { - /// Returns the [`Ok`] value if `self` is `Ok`, and the [`Err`] value if - /// `self` is `Err`. - /// - /// In other words, this function returns the value (the `T`) of a - /// `Result<T, T>`, regardless of whether or not that result is `Ok` or - /// `Err`. - /// - /// This can be useful in conjunction with APIs such as - /// [`Atomic*::compare_exchange`], or [`slice::binary_search`], but only in - /// cases where you don't care if the result was `Ok` or not. - /// - /// [`Atomic*::compare_exchange`]: crate::sync::atomic::AtomicBool::compare_exchange - /// - /// # Examples - /// - /// ``` - /// #![feature(result_into_ok_or_err)] - /// let ok: Result<u32, u32> = Ok(3); - /// let err: Result<u32, u32> = Err(4); - /// - /// assert_eq!(ok.into_ok_or_err(), 3); - /// assert_eq!(err.into_ok_or_err(), 4); - /// ``` - #[inline] - #[unstable(feature = "result_into_ok_or_err", reason = "newly added", issue = "82223")] - pub const fn into_ok_or_err(self) -> T { - match self { - Ok(v) => v, - Err(v) => v, - } - } -} - // This is a separate function to reduce the code size of the methods #[cfg(not(feature = "panic_immediate_abort"))] #[inline(never)] @@ -2095,9 +2072,6 @@ impl<A, E, V: FromIterator<A>> FromIterator<Result<A, E>> for Result<V, E> { /// so the final value of `shared` is 6 (= `3 + 2 + 1`), not 16. #[inline] fn from_iter<I: IntoIterator<Item = Result<A, E>>>(iter: I) -> Result<V, E> { - // FIXME(#11084): This could be replaced with Iterator::scan when this - // performance bug is closed. - iter::try_process(iter.into_iter(), |i| i.collect()) } } @@ -2145,6 +2119,7 @@ impl<T, E, F: From<E>> ops::FromResidual<ops::Yeet<E>> for Result<T, F> { } #[unstable(feature = "try_trait_v2_residual", issue = "91285")] -impl<T, E> ops::Residual<T> for Result<convert::Infallible, E> { +#[rustc_const_unstable(feature = "const_try", issue = "74935")] +impl<T, E> const ops::Residual<T> for Result<convert::Infallible, E> { type TryType = Result<T, E>; } diff --git a/library/core/src/slice/ascii.rs b/library/core/src/slice/ascii.rs index 63715a6b8..5e5399acc 100644 --- a/library/core/src/slice/ascii.rs +++ b/library/core/src/slice/ascii.rs @@ -215,8 +215,6 @@ impl<'a> iter::DoubleEndedIterator for EscapeAscii<'a> { } } #[stable(feature = "inherent_ascii_escape", since = "1.60.0")] -impl<'a> iter::ExactSizeIterator for EscapeAscii<'a> {} -#[stable(feature = "inherent_ascii_escape", since = "1.60.0")] impl<'a> iter::FusedIterator for EscapeAscii<'a> {} #[stable(feature = "inherent_ascii_escape", since = "1.60.0")] impl<'a> fmt::Display for EscapeAscii<'a> { diff --git a/library/core/src/slice/index.rs b/library/core/src/slice/index.rs index fd7ecf3da..6d2f7330d 100644 --- a/library/core/src/slice/index.rs +++ b/library/core/src/slice/index.rs @@ -48,10 +48,12 @@ const fn slice_start_index_len_fail(index: usize, len: usize) -> ! { } // FIXME const-hack +#[track_caller] fn slice_start_index_len_fail_rt(index: usize, len: usize) -> ! { panic!("range start index {index} out of range for slice of length {len}"); } +#[track_caller] const fn slice_start_index_len_fail_ct(_: usize, _: usize) -> ! { panic!("slice start index is out of range for slice"); } @@ -69,10 +71,12 @@ const fn slice_end_index_len_fail(index: usize, len: usize) -> ! { } // FIXME const-hack +#[track_caller] fn slice_end_index_len_fail_rt(index: usize, len: usize) -> ! { panic!("range end index {index} out of range for slice of length {len}"); } +#[track_caller] const fn slice_end_index_len_fail_ct(_: usize, _: usize) -> ! { panic!("slice end index is out of range for slice"); } @@ -88,10 +92,12 @@ const fn slice_index_order_fail(index: usize, end: usize) -> ! { } // FIXME const-hack +#[track_caller] fn slice_index_order_fail_rt(index: usize, end: usize) -> ! { panic!("slice index starts at {index} but ends at {end}"); } +#[track_caller] const fn slice_index_order_fail_ct(_: usize, _: usize) -> ! { panic!("slice index start is larger than end"); } @@ -133,6 +139,8 @@ mod private_slice_index { impl Sealed for ops::RangeToInclusive<usize> {} #[stable(feature = "slice_index_with_ops_bound_pair", since = "1.53.0")] impl Sealed for (ops::Bound<usize>, ops::Bound<usize>) {} + + impl Sealed for ops::IndexRange {} } /// A helper trait used for indexing operations. @@ -152,6 +160,7 @@ mod private_slice_index { message = "the type `{T}` cannot be indexed by `{Self}`", label = "slice indices are of type `usize` or ranges of `usize`" )] +#[const_trait] pub unsafe trait SliceIndex<T: ?Sized>: private_slice_index::Sealed { /// The output type returned by methods. #[stable(feature = "slice_get_slice", since = "1.28.0")] @@ -217,21 +226,29 @@ unsafe impl<T> const SliceIndex<[T]> for usize { #[inline] unsafe fn get_unchecked(self, slice: *const [T]) -> *const T { + let this = self; // SAFETY: the caller guarantees that `slice` is not dangling, so it // cannot be longer than `isize::MAX`. They also guarantee that // `self` is in bounds of `slice` so `self` cannot overflow an `isize`, // so the call to `add` is safe. unsafe { - assert_unsafe_precondition!(self < slice.len()); + assert_unsafe_precondition!( + "slice::get_unchecked requires that the index is within the slice", + [T](this: usize, slice: *const [T]) => this < slice.len() + ); slice.as_ptr().add(self) } } #[inline] unsafe fn get_unchecked_mut(self, slice: *mut [T]) -> *mut T { + let this = self; // SAFETY: see comments for `get_unchecked` above. unsafe { - assert_unsafe_precondition!(self < slice.len()); + assert_unsafe_precondition!( + "slice::get_unchecked_mut requires that the index is within the slice", + [T](this: usize, slice: *mut [T]) => this < slice.len() + ); slice.as_mut_ptr().add(self) } } @@ -249,6 +266,83 @@ unsafe impl<T> const SliceIndex<[T]> for usize { } } +/// Because `IndexRange` guarantees `start <= end`, fewer checks are needed here +/// than there are for a general `Range<usize>` (which might be `100..3`). +#[rustc_const_unstable(feature = "const_index_range_slice_index", issue = "none")] +unsafe impl<T> const SliceIndex<[T]> for ops::IndexRange { + type Output = [T]; + + #[inline] + fn get(self, slice: &[T]) -> Option<&[T]> { + if self.end() <= slice.len() { + // SAFETY: `self` is checked to be valid and in bounds above. + unsafe { Some(&*self.get_unchecked(slice)) } + } else { + None + } + } + + #[inline] + fn get_mut(self, slice: &mut [T]) -> Option<&mut [T]> { + if self.end() <= slice.len() { + // SAFETY: `self` is checked to be valid and in bounds above. + unsafe { Some(&mut *self.get_unchecked_mut(slice)) } + } else { + None + } + } + + #[inline] + unsafe fn get_unchecked(self, slice: *const [T]) -> *const [T] { + let end = self.end(); + // SAFETY: the caller guarantees that `slice` is not dangling, so it + // cannot be longer than `isize::MAX`. They also guarantee that + // `self` is in bounds of `slice` so `self` cannot overflow an `isize`, + // so the call to `add` is safe. + + unsafe { + assert_unsafe_precondition!( + "slice::get_unchecked requires that the index is within the slice", + [T](end: usize, slice: *const [T]) => end <= slice.len() + ); + ptr::slice_from_raw_parts(slice.as_ptr().add(self.start()), self.len()) + } + } + + #[inline] + unsafe fn get_unchecked_mut(self, slice: *mut [T]) -> *mut [T] { + let end = self.end(); + // SAFETY: see comments for `get_unchecked` above. + unsafe { + assert_unsafe_precondition!( + "slice::get_unchecked_mut requires that the index is within the slice", + [T](end: usize, slice: *mut [T]) => end <= slice.len() + ); + ptr::slice_from_raw_parts_mut(slice.as_mut_ptr().add(self.start()), self.len()) + } + } + + #[inline] + fn index(self, slice: &[T]) -> &[T] { + if self.end() <= slice.len() { + // SAFETY: `self` is checked to be valid and in bounds above. + unsafe { &*self.get_unchecked(slice) } + } else { + slice_end_index_len_fail(self.end(), slice.len()) + } + } + + #[inline] + fn index_mut(self, slice: &mut [T]) -> &mut [T] { + if self.end() <= slice.len() { + // SAFETY: `self` is checked to be valid and in bounds above. + unsafe { &mut *self.get_unchecked_mut(slice) } + } else { + slice_end_index_len_fail(self.end(), slice.len()) + } + } +} + #[stable(feature = "slice_get_slice_impls", since = "1.15.0")] #[rustc_const_unstable(feature = "const_slice_index", issue = "none")] unsafe impl<T> const SliceIndex<[T]> for ops::Range<usize> { @@ -276,22 +370,32 @@ unsafe impl<T> const SliceIndex<[T]> for ops::Range<usize> { #[inline] unsafe fn get_unchecked(self, slice: *const [T]) -> *const [T] { + let this = ops::Range { start: self.start, end: self.end }; // SAFETY: the caller guarantees that `slice` is not dangling, so it // cannot be longer than `isize::MAX`. They also guarantee that // `self` is in bounds of `slice` so `self` cannot overflow an `isize`, // so the call to `add` is safe. unsafe { - assert_unsafe_precondition!(self.end >= self.start && self.end <= slice.len()); + assert_unsafe_precondition!( + "slice::get_unchecked requires that the range is within the slice", + [T](this: ops::Range<usize>, slice: *const [T]) => + this.end >= this.start && this.end <= slice.len() + ); ptr::slice_from_raw_parts(slice.as_ptr().add(self.start), self.end - self.start) } } #[inline] unsafe fn get_unchecked_mut(self, slice: *mut [T]) -> *mut [T] { + let this = ops::Range { start: self.start, end: self.end }; // SAFETY: see comments for `get_unchecked` above. unsafe { - assert_unsafe_precondition!(self.end >= self.start && self.end <= slice.len()); + assert_unsafe_precondition!( + "slice::get_unchecked_mut requires that the range is within the slice", + [T](this: ops::Range<usize>, slice: *mut [T]) => + this.end >= this.start && this.end <= slice.len() + ); ptr::slice_from_raw_parts_mut(slice.as_mut_ptr().add(self.start), self.end - self.start) } } diff --git a/library/core/src/slice/iter.rs b/library/core/src/slice/iter.rs index f1e659309..8a8962828 100644 --- a/library/core/src/slice/iter.rs +++ b/library/core/src/slice/iter.rs @@ -9,7 +9,7 @@ use crate::fmt; use crate::intrinsics::{assume, exact_div, unchecked_sub}; use crate::iter::{FusedIterator, TrustedLen, TrustedRandomAccess, TrustedRandomAccessNoCoerce}; use crate::marker::{PhantomData, Send, Sized, Sync}; -use crate::mem; +use crate::mem::{self, SizedTypeProperties}; use crate::num::NonZeroUsize; use crate::ptr::NonNull; @@ -91,11 +91,8 @@ impl<'a, T> Iter<'a, T> { unsafe { assume(!ptr.is_null()); - let end = if mem::size_of::<T>() == 0 { - (ptr as *const u8).wrapping_add(slice.len()) as *const T - } else { - ptr.add(slice.len()) - }; + let end = + if T::IS_ZST { ptr.wrapping_byte_add(slice.len()) } else { ptr.add(slice.len()) }; Self { ptr: NonNull::new_unchecked(ptr as *mut T), end, _marker: PhantomData } } @@ -127,6 +124,7 @@ impl<'a, T> Iter<'a, T> { /// ``` #[must_use] #[stable(feature = "iter_to_slice", since = "1.4.0")] + #[inline] pub fn as_slice(&self) -> &'a [T] { self.make_slice() } @@ -146,6 +144,7 @@ iterator! {struct Iter -> *const T, &'a T, const, {/* no mut */}, { #[stable(feature = "rust1", since = "1.0.0")] impl<T> Clone for Iter<'_, T> { + #[inline] fn clone(&self) -> Self { Iter { ptr: self.ptr, end: self.end, _marker: self._marker } } @@ -153,6 +152,7 @@ impl<T> Clone for Iter<'_, T> { #[stable(feature = "slice_iter_as_ref", since = "1.13.0")] impl<T> AsRef<[T]> for Iter<'_, T> { + #[inline] fn as_ref(&self) -> &[T] { self.as_slice() } @@ -227,11 +227,8 @@ impl<'a, T> IterMut<'a, T> { unsafe { assume(!ptr.is_null()); - let end = if mem::size_of::<T>() == 0 { - (ptr as *mut u8).wrapping_add(slice.len()) as *mut T - } else { - ptr.add(slice.len()) - }; + let end = + if T::IS_ZST { ptr.wrapping_byte_add(slice.len()) } else { ptr.add(slice.len()) }; Self { ptr: NonNull::new_unchecked(ptr), end, _marker: PhantomData } } @@ -303,6 +300,7 @@ impl<'a, T> IterMut<'a, T> { /// ``` #[must_use] #[stable(feature = "slice_iter_mut_as_slice", since = "1.53.0")] + #[inline] pub fn as_slice(&self) -> &[T] { self.make_slice() } @@ -351,6 +349,7 @@ impl<'a, T> IterMut<'a, T> { #[stable(feature = "slice_iter_mut_as_slice", since = "1.53.0")] impl<T> AsRef<[T]> for IterMut<'_, T> { + #[inline] fn as_ref(&self) -> &[T] { self.as_slice() } @@ -2754,10 +2753,10 @@ impl<'a, T> Iterator for RChunksMut<'a, T> { None => 0, }; // SAFETY: This type ensures that self.v is a valid pointer with a correct len. - // Therefore the bounds check in split_at_mut guarantess the split point is inbounds. + // Therefore the bounds check in split_at_mut guarantees the split point is inbounds. let (head, tail) = unsafe { self.v.split_at_mut(start) }; // SAFETY: This type ensures that self.v is a valid pointer with a correct len. - // Therefore the bounds check in split_at_mut guarantess the split point is inbounds. + // Therefore the bounds check in split_at_mut guarantees the split point is inbounds. let (nth, _) = unsafe { tail.split_at_mut(end - start) }; self.v = head; // SAFETY: Nothing else points to or will point to the contents of this slice. diff --git a/library/core/src/slice/iter/macros.rs b/library/core/src/slice/iter/macros.rs index c05242222..ce51d48e3 100644 --- a/library/core/src/slice/iter/macros.rs +++ b/library/core/src/slice/iter/macros.rs @@ -64,7 +64,7 @@ macro_rules! iterator { // backwards by `n`. `n` must not exceed `self.len()`. macro_rules! zst_shrink { ($self: ident, $n: ident) => { - $self.end = ($self.end as * $raw_mut u8).wrapping_offset(-$n) as * $raw_mut T; + $self.end = $self.end.wrapping_byte_sub($n); } } @@ -82,7 +82,7 @@ macro_rules! iterator { // returning the old start. // Unsafe because the offset must not exceed `self.len()`. #[inline(always)] - unsafe fn post_inc_start(&mut self, offset: isize) -> * $raw_mut T { + unsafe fn post_inc_start(&mut self, offset: usize) -> * $raw_mut T { if mem::size_of::<T>() == 0 { zst_shrink!(self, offset); self.ptr.as_ptr() @@ -90,7 +90,7 @@ macro_rules! iterator { let old = self.ptr.as_ptr(); // SAFETY: the caller guarantees that `offset` doesn't exceed `self.len()`, // so this new pointer is inside `self` and thus guaranteed to be non-null. - self.ptr = unsafe { NonNull::new_unchecked(self.ptr.as_ptr().offset(offset)) }; + self.ptr = unsafe { NonNull::new_unchecked(self.ptr.as_ptr().add(offset)) }; old } } @@ -99,15 +99,15 @@ macro_rules! iterator { // returning the new end. // Unsafe because the offset must not exceed `self.len()`. #[inline(always)] - unsafe fn pre_dec_end(&mut self, offset: isize) -> * $raw_mut T { - if mem::size_of::<T>() == 0 { + unsafe fn pre_dec_end(&mut self, offset: usize) -> * $raw_mut T { + if T::IS_ZST { zst_shrink!(self, offset); self.ptr.as_ptr() } else { // SAFETY: the caller guarantees that `offset` doesn't exceed `self.len()`, // which is guaranteed to not overflow an `isize`. Also, the resulting pointer // is in bounds of `slice`, which fulfills the other requirements for `offset`. - self.end = unsafe { self.end.offset(-offset) }; + self.end = unsafe { self.end.sub(offset) }; self.end } } @@ -140,7 +140,7 @@ macro_rules! iterator { // since we check if the iterator is empty first. unsafe { assume(!self.ptr.as_ptr().is_null()); - if mem::size_of::<T>() != 0 { + if !<T>::IS_ZST { assume(!self.end.is_null()); } if is_empty!(self) { @@ -166,7 +166,7 @@ macro_rules! iterator { fn nth(&mut self, n: usize) -> Option<$elem> { if n >= len!(self) { // This iterator is now empty. - if mem::size_of::<T>() == 0 { + if T::IS_ZST { // We have to do it this way as `ptr` may never be 0, but `end` // could be (due to wrapping). self.end = self.ptr.as_ptr(); @@ -180,7 +180,7 @@ macro_rules! iterator { } // SAFETY: We are in bounds. `post_inc_start` does the right thing even for ZSTs. unsafe { - self.post_inc_start(n as isize); + self.post_inc_start(n); Some(next_unchecked!(self)) } } @@ -189,7 +189,7 @@ macro_rules! iterator { fn advance_by(&mut self, n: usize) -> Result<(), usize> { let advance = cmp::min(len!(self), n); // SAFETY: By construction, `advance` does not exceed `self.len()`. - unsafe { self.post_inc_start(advance as isize) }; + unsafe { self.post_inc_start(advance) }; if advance == n { Ok(()) } else { Err(advance) } } @@ -355,7 +355,7 @@ macro_rules! iterator { // empty first. unsafe { assume(!self.ptr.as_ptr().is_null()); - if mem::size_of::<T>() != 0 { + if !<T>::IS_ZST { assume(!self.end.is_null()); } if is_empty!(self) { @@ -375,7 +375,7 @@ macro_rules! iterator { } // SAFETY: We are in bounds. `pre_dec_end` does the right thing even for ZSTs. unsafe { - self.pre_dec_end(n as isize); + self.pre_dec_end(n); Some(next_back_unchecked!(self)) } } @@ -384,7 +384,7 @@ macro_rules! iterator { fn advance_back_by(&mut self, n: usize) -> Result<(), usize> { let advance = cmp::min(len!(self), n); // SAFETY: By construction, `advance` does not exceed `self.len()`. - unsafe { self.pre_dec_end(advance as isize) }; + unsafe { self.pre_dec_end(advance) }; if advance == n { Ok(()) } else { Err(advance) } } } diff --git a/library/core/src/slice/memchr.rs b/library/core/src/slice/memchr.rs index dffeaf6a8..c848c2e18 100644 --- a/library/core/src/slice/memchr.rs +++ b/library/core/src/slice/memchr.rs @@ -16,35 +16,51 @@ const USIZE_BYTES: usize = mem::size_of::<usize>(); /// bytes where the borrow propagated all the way to the most significant /// bit." #[inline] -fn contains_zero_byte(x: usize) -> bool { +const fn contains_zero_byte(x: usize) -> bool { x.wrapping_sub(LO_USIZE) & !x & HI_USIZE != 0 } #[cfg(target_pointer_width = "16")] #[inline] -fn repeat_byte(b: u8) -> usize { +const fn repeat_byte(b: u8) -> usize { (b as usize) << 8 | b as usize } #[cfg(not(target_pointer_width = "16"))] #[inline] -fn repeat_byte(b: u8) -> usize { +const fn repeat_byte(b: u8) -> usize { (b as usize) * (usize::MAX / 255) } /// Returns the first index matching the byte `x` in `text`. #[must_use] #[inline] -pub fn memchr(x: u8, text: &[u8]) -> Option<usize> { - // Fast path for small slices +pub const fn memchr(x: u8, text: &[u8]) -> Option<usize> { + // Fast path for small slices. if text.len() < 2 * USIZE_BYTES { - return text.iter().position(|elt| *elt == x); + return memchr_naive(x, text); } - memchr_general_case(x, text) + memchr_aligned(x, text) } -fn memchr_general_case(x: u8, text: &[u8]) -> Option<usize> { +#[inline] +const fn memchr_naive(x: u8, text: &[u8]) -> Option<usize> { + let mut i = 0; + + // FIXME(const-hack): Replace with `text.iter().pos(|c| *c == x)`. + while i < text.len() { + if text[i] == x { + return Some(i); + } + + i += 1; + } + + None +} + +const fn memchr_aligned(x: u8, text: &[u8]) -> Option<usize> { // Scan for a single byte value by reading two `usize` words at a time. // // Split `text` in three parts @@ -59,7 +75,7 @@ fn memchr_general_case(x: u8, text: &[u8]) -> Option<usize> { if offset > 0 { offset = cmp::min(offset, len); - if let Some(index) = text[..offset].iter().position(|elt| *elt == x) { + if let Some(index) = memchr_naive(x, &text[..offset]) { return Some(index); } } @@ -84,7 +100,8 @@ fn memchr_general_case(x: u8, text: &[u8]) -> Option<usize> { } // Find the byte after the point the body loop stopped. - text[offset..].iter().position(|elt| *elt == x).map(|i| offset + i) + // FIXME(const-hack): Use `?` instead. + if let Some(i) = memchr_naive(x, &text[offset..]) { Some(offset + i) } else { None } } /// Returns the last index matching the byte `x` in `text`. @@ -124,8 +141,8 @@ pub fn memrchr(x: u8, text: &[u8]) -> Option<usize> { // SAFETY: offset starts at len - suffix.len(), as long as it is greater than // min_aligned_offset (prefix.len()) the remaining distance is at least 2 * chunk_bytes. unsafe { - let u = *(ptr.offset(offset as isize - 2 * chunk_bytes as isize) as *const Chunk); - let v = *(ptr.offset(offset as isize - chunk_bytes as isize) as *const Chunk); + let u = *(ptr.add(offset - 2 * chunk_bytes) as *const Chunk); + let v = *(ptr.add(offset - chunk_bytes) as *const Chunk); // Break if there is a matching byte. let zu = contains_zero_byte(u ^ repeated_x); diff --git a/library/core/src/slice/mod.rs b/library/core/src/slice/mod.rs index e6ca6ef82..4f1bb1734 100644 --- a/library/core/src/slice/mod.rs +++ b/library/core/src/slice/mod.rs @@ -9,7 +9,7 @@ use crate::cmp::Ordering::{self, Greater, Less}; use crate::intrinsics::{assert_unsafe_precondition, exact_div}; use crate::marker::Copy; -use crate::mem; +use crate::mem::{self, SizedTypeProperties}; use crate::num::NonZeroUsize; use crate::ops::{Bound, FnMut, OneSidedRange, Range, RangeBounds}; use crate::option::Option; @@ -123,18 +123,11 @@ impl<T> [T] { #[lang = "slice_len_fn"] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_slice_len", since = "1.39.0")] + #[rustc_allow_const_fn_unstable(ptr_metadata)] #[inline] #[must_use] - // SAFETY: const sound because we transmute out the length field as a usize (which it must be) pub const fn len(&self) -> usize { - // FIXME: Replace with `crate::ptr::metadata(self)` when that is const-stable. - // As of this writing this causes a "Const-stable functions can only call other - // const-stable functions" error. - - // SAFETY: Accessing the value from the `PtrRepr` union is safe since *const T - // and PtrComponents<T> have the same memory layouts. Only std can make this - // guarantee. - unsafe { crate::ptr::PtrRepr { const_ptr: self }.components.metadata } + ptr::metadata(self) } /// Returns `true` if the slice has a length of 0. @@ -656,10 +649,14 @@ impl<T> [T] { #[unstable(feature = "slice_swap_unchecked", issue = "88539")] #[rustc_const_unstable(feature = "const_swap", issue = "83163")] pub const unsafe fn swap_unchecked(&mut self, a: usize, b: usize) { - let ptr = self.as_mut_ptr(); + let this = self; + let ptr = this.as_mut_ptr(); // SAFETY: caller has to guarantee that `a < self.len()` and `b < self.len()` unsafe { - assert_unsafe_precondition!(a < self.len() && b < self.len()); + assert_unsafe_precondition!( + "slice::swap_unchecked requires that the indices are within the slice", + [T](a: usize, b: usize, this: &mut [T]) => a < this.len() && b < this.len() + ); ptr::swap(ptr.add(a), ptr.add(b)); } } @@ -674,8 +671,9 @@ impl<T> [T] { /// assert!(v == [3, 2, 1]); /// ``` #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_reverse", issue = "100784")] #[inline] - pub fn reverse(&mut self) { + pub const fn reverse(&mut self) { let half_len = self.len() / 2; let Range { start, end } = self.as_mut_ptr_range(); @@ -698,9 +696,9 @@ impl<T> [T] { revswap(front_half, back_half, half_len); #[inline] - fn revswap<T>(a: &mut [T], b: &mut [T], n: usize) { - debug_assert_eq!(a.len(), n); - debug_assert_eq!(b.len(), n); + const fn revswap<T>(a: &mut [T], b: &mut [T], n: usize) { + debug_assert!(a.len() == n); + debug_assert!(b.len() == n); // Because this function is first compiled in isolation, // this check tells LLVM that the indexing below is @@ -708,8 +706,10 @@ impl<T> [T] { // lengths of the slices are known -- it's removed. let (a, b) = (&mut a[..n], &mut b[..n]); - for i in 0..n { + let mut i = 0; + while i < n { mem::swap(&mut a[i], &mut b[n - 1 - i]); + i += 1; } } } @@ -969,9 +969,13 @@ impl<T> [T] { #[inline] #[must_use] pub unsafe fn as_chunks_unchecked<const N: usize>(&self) -> &[[T; N]] { + let this = self; // SAFETY: Caller must guarantee that `N` is nonzero and exactly divides the slice length let new_len = unsafe { - assert_unsafe_precondition!(N != 0 && self.len() % N == 0); + assert_unsafe_precondition!( + "slice::as_chunks_unchecked requires `N != 0` and the slice to split exactly into `N`-element chunks", + [T](this: &[T], N: usize) => N != 0 && this.len() % N == 0 + ); exact_div(self.len(), N) }; // SAFETY: We cast a slice of `new_len * N` elements into @@ -1108,10 +1112,14 @@ impl<T> [T] { #[inline] #[must_use] pub unsafe fn as_chunks_unchecked_mut<const N: usize>(&mut self) -> &mut [[T; N]] { + let this = &*self; // SAFETY: Caller must guarantee that `N` is nonzero and exactly divides the slice length let new_len = unsafe { - assert_unsafe_precondition!(N != 0 && self.len() % N == 0); - exact_div(self.len(), N) + assert_unsafe_precondition!( + "slice::as_chunks_unchecked_mut requires `N != 0` and the slice to split exactly into `N`-element chunks", + [T](this: &[T], N: usize) => N != 0 && this.len() % N == 0 + ); + exact_div(this.len(), N) }; // SAFETY: We cast a slice of `new_len * N` elements into // a slice of `new_len` many `N` elements chunks. @@ -1538,13 +1546,14 @@ impl<T> [T] { /// } /// ``` #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_slice_split_at_not_mut", issue = "101158")] #[inline] #[track_caller] #[must_use] - pub fn split_at(&self, mid: usize) -> (&[T], &[T]) { + pub const fn split_at(&self, mid: usize) -> (&[T], &[T]) { assert!(mid <= self.len()); // SAFETY: `[ptr; mid]` and `[mid; len]` are inside `self`, which - // fulfills the requirements of `from_raw_parts_mut`. + // fulfills the requirements of `split_at_unchecked`. unsafe { self.split_at_unchecked(mid) } } @@ -1573,7 +1582,8 @@ impl<T> [T] { #[inline] #[track_caller] #[must_use] - pub fn split_at_mut(&mut self, mid: usize) -> (&mut [T], &mut [T]) { + #[rustc_const_unstable(feature = "const_slice_split_at_mut", issue = "101804")] + pub const fn split_at_mut(&mut self, mid: usize) -> (&mut [T], &mut [T]) { assert!(mid <= self.len()); // SAFETY: `[ptr; mid]` and `[mid; len]` are inside `self`, which // fulfills the requirements of `from_raw_parts_mut`. @@ -1623,11 +1633,19 @@ impl<T> [T] { /// } /// ``` #[unstable(feature = "slice_split_at_unchecked", reason = "new API", issue = "76014")] + #[rustc_const_unstable(feature = "slice_split_at_unchecked", issue = "76014")] #[inline] #[must_use] - pub unsafe fn split_at_unchecked(&self, mid: usize) -> (&[T], &[T]) { + pub const unsafe fn split_at_unchecked(&self, mid: usize) -> (&[T], &[T]) { + // HACK: the const function `from_raw_parts` is used to make this + // function const; previously the implementation used + // `(self.get_unchecked(..mid), self.get_unchecked(mid..))` + + let len = self.len(); + let ptr = self.as_ptr(); + // SAFETY: Caller has to check that `0 <= mid <= self.len()` - unsafe { (self.get_unchecked(..mid), self.get_unchecked(mid..)) } + unsafe { (from_raw_parts(ptr, mid), from_raw_parts(ptr.add(mid), len - mid)) } } /// Divides one mutable slice into two at an index, without doing bounds checking. @@ -1664,9 +1682,10 @@ impl<T> [T] { /// assert_eq!(v, [1, 2, 3, 4, 5, 6]); /// ``` #[unstable(feature = "slice_split_at_unchecked", reason = "new API", issue = "76014")] + #[rustc_const_unstable(feature = "const_slice_split_at_mut", issue = "101804")] #[inline] #[must_use] - pub unsafe fn split_at_mut_unchecked(&mut self, mid: usize) -> (&mut [T], &mut [T]) { + pub const unsafe fn split_at_mut_unchecked(&mut self, mid: usize) -> (&mut [T], &mut [T]) { let len = self.len(); let ptr = self.as_mut_ptr(); @@ -1675,7 +1694,10 @@ impl<T> [T] { // `[ptr; mid]` and `[mid; len]` are not overlapping, so returning a mutable reference // is fine. unsafe { - assert_unsafe_precondition!(mid <= len); + assert_unsafe_precondition!( + "slice::split_at_mut_unchecked requires the index to be within the slice", + (mid: usize, len: usize) => mid <= len + ); (from_raw_parts_mut(ptr, mid), from_raw_parts_mut(ptr.add(mid), len - mid)) } } @@ -2059,7 +2081,7 @@ impl<T> [T] { SplitN::new(self.split(pred), n) } - /// Returns an iterator over subslices separated by elements that match + /// Returns an iterator over mutable subslices separated by elements that match /// `pred`, limited to returning at most `n` items. The matched element is /// not contained in the subslices. /// @@ -2309,7 +2331,7 @@ impl<T> [T] { } /// Binary searches this slice for a given element. - /// This behaves similary to [`contains`] if this slice is sorted. + /// This behaves similarly to [`contains`] if this slice is sorted. /// /// If the value is found then [`Result::Ok`] is returned, containing the /// index of the matching element. If there are multiple matches, then any @@ -2342,6 +2364,28 @@ impl<T> [T] { /// assert!(match r { Ok(1..=4) => true, _ => false, }); /// ``` /// + /// If you want to find that whole *range* of matching items, rather than + /// an arbitrary matching one, that can be done using [`partition_point`]: + /// ``` + /// let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]; + /// + /// let low = s.partition_point(|x| x < &1); + /// assert_eq!(low, 1); + /// let high = s.partition_point(|x| x <= &1); + /// assert_eq!(high, 5); + /// let r = s.binary_search(&1); + /// assert!((low..high).contains(&r.unwrap())); + /// + /// assert!(s[..low].iter().all(|&x| x < 1)); + /// assert!(s[low..high].iter().all(|&x| x == 1)); + /// assert!(s[high..].iter().all(|&x| x > 1)); + /// + /// // For something not found, the "range" of equal items is empty + /// assert_eq!(s.partition_point(|x| x < &11), 9); + /// assert_eq!(s.partition_point(|x| x <= &11), 9); + /// assert_eq!(s.binary_search(&11), Err(9)); + /// ``` + /// /// If you want to insert an item to a sorted vector, while maintaining /// sort order, consider using [`partition_point`]: /// @@ -2409,15 +2453,20 @@ impl<T> [T] { where F: FnMut(&'a T) -> Ordering, { + // INVARIANTS: + // - 0 <= left <= left + size = right <= self.len() + // - f returns Less for everything in self[..left] + // - f returns Greater for everything in self[right..] let mut size = self.len(); let mut left = 0; let mut right = size; while left < right { let mid = left + size / 2; - // SAFETY: the call is made safe by the following invariants: - // - `mid >= 0` - // - `mid < size`: `mid` is limited by `[left; right)` bound. + // SAFETY: the while condition means `size` is strictly positive, so + // `size/2 < size`. Thus `left + size/2 < left + size`, which + // coupled with the `left + size <= self.len()` invariant means + // we have `left + size/2 < self.len()`, and this is in-bounds. let cmp = f(unsafe { self.get_unchecked(mid) }); // The reason why we use if/else control flow rather than match @@ -2435,6 +2484,10 @@ impl<T> [T] { size = right - left; } + + // SAFETY: directly true from the overall invariant. + // Note that this is `<=`, unlike the assume in the `Ok` path. + unsafe { crate::intrinsics::assume(left <= self.len()) }; Err(left) } @@ -2525,7 +2578,7 @@ impl<T> [T] { where T: Ord, { - sort::quicksort(self, |a, b| a.lt(b)); + sort::quicksort(self, T::lt); } /// Sorts the slice with a comparator function, but might not preserve the order of equal @@ -2628,9 +2681,10 @@ impl<T> [T] { /// less than or equal to any value at a position `j > index`. Additionally, this reordering is /// unstable (i.e. any number of equal elements may end up at position `index`), in-place /// (i.e. does not allocate), and *O*(*n*) worst-case. This function is also/ known as "kth - /// element" in other libraries. It returns a triplet of the following values: all elements less - /// than the one at the given index, the value at the given index, and all elements greater than - /// the one at the given index. + /// element" in other libraries. It returns a triplet of the following from the reordered slice: + /// the subslice prior to `index`, the element at `index`, and the subslice after `index`; + /// accordingly, the values in those two subslices will respectively all be less-than-or-equal-to + /// and greater-than-or-equal-to the value of the element at `index`. /// /// # Current implementation /// @@ -2664,8 +2718,7 @@ impl<T> [T] { where T: Ord, { - let mut f = |a: &T, b: &T| a.lt(b); - sort::partition_at_index(self, index, &mut f) + sort::partition_at_index(self, index, T::lt) } /// Reorder the slice with a comparator function such that the element at `index` is at its @@ -2675,10 +2728,11 @@ impl<T> [T] { /// less than or equal to any value at a position `j > index` using the comparator function. /// Additionally, this reordering is unstable (i.e. any number of equal elements may end up at /// position `index`), in-place (i.e. does not allocate), and *O*(*n*) worst-case. This function - /// is also known as "kth element" in other libraries. It returns a triplet of the following - /// values: all elements less than the one at the given index, the value at the given index, - /// and all elements greater than the one at the given index, using the provided comparator - /// function. + /// is also known as "kth element" in other libraries. It returns a triplet of the following from + /// the slice reordered according to the provided comparator function: the subslice prior to + /// `index`, the element at `index`, and the subslice after `index`; accordingly, the values in + /// those two subslices will respectively all be less-than-or-equal-to and greater-than-or-equal-to + /// the value of the element at `index`. /// /// # Current implementation /// @@ -2716,8 +2770,7 @@ impl<T> [T] { where F: FnMut(&T, &T) -> Ordering, { - let mut f = |a: &T, b: &T| compare(a, b) == Less; - sort::partition_at_index(self, index, &mut f) + sort::partition_at_index(self, index, |a: &T, b: &T| compare(a, b) == Less) } /// Reorder the slice with a key extraction function such that the element at `index` is at its @@ -2727,10 +2780,11 @@ impl<T> [T] { /// less than or equal to any value at a position `j > index` using the key extraction function. /// Additionally, this reordering is unstable (i.e. any number of equal elements may end up at /// position `index`), in-place (i.e. does not allocate), and *O*(*n*) worst-case. This function - /// is also known as "kth element" in other libraries. It returns a triplet of the following - /// values: all elements less than the one at the given index, the value at the given index, and - /// all elements greater than the one at the given index, using the provided key extraction - /// function. + /// is also known as "kth element" in other libraries. It returns a triplet of the following from + /// the slice reordered according to the provided key extraction function: the subslice prior to + /// `index`, the element at `index`, and the subslice after `index`; accordingly, the values in + /// those two subslices will respectively all be less-than-or-equal-to and greater-than-or-equal-to + /// the value of the element at `index`. /// /// # Current implementation /// @@ -2769,8 +2823,7 @@ impl<T> [T] { F: FnMut(&T) -> K, K: Ord, { - let mut g = |a: &T, b: &T| f(a).lt(&f(b)); - sort::partition_at_index(self, index, &mut g) + sort::partition_at_index(self, index, |a: &T, b: &T| f(a).lt(&f(b))) } /// Moves all consecutive repeated elements to the end of the slice according to the @@ -2921,7 +2974,7 @@ impl<T> [T] { let prev_ptr_write = ptr.add(next_write - 1); if !same_bucket(&mut *ptr_read, &mut *prev_ptr_write) { if next_read != next_write { - let ptr_write = prev_ptr_write.offset(1); + let ptr_write = prev_ptr_write.add(1); mem::swap(&mut *ptr_read, &mut *ptr_write); } next_write += 1; @@ -3444,7 +3497,7 @@ impl<T> [T] { #[must_use] pub unsafe fn align_to<U>(&self) -> (&[T], &[U], &[T]) { // Note that most of this function will be constant-evaluated, - if mem::size_of::<U>() == 0 || mem::size_of::<T>() == 0 { + if U::IS_ZST || T::IS_ZST { // handle ZSTs specially, which is – don't handle them at all. return (self, &[], &[]); } @@ -3505,7 +3558,7 @@ impl<T> [T] { #[must_use] pub unsafe fn align_to_mut<U>(&mut self) -> (&mut [T], &mut [U], &mut [T]) { // Note that most of this function will be constant-evaluated, - if mem::size_of::<U>() == 0 || mem::size_of::<T>() == 0 { + if U::IS_ZST || T::IS_ZST { // handle ZSTs specially, which is – don't handle them at all. return (self, &mut [], &mut []); } @@ -3518,7 +3571,7 @@ impl<T> [T] { // alignment targeted for U. // `crate::ptr::align_offset` is called with a correctly aligned and // valid pointer `ptr` (it comes from a reference to `self`) and with - // a size that is a power of two (since it comes from the alignement for U), + // a size that is a power of two (since it comes from the alignment for U), // satisfying its safety constraints. let offset = unsafe { crate::ptr::align_offset(ptr, mem::align_of::<U>()) }; if offset > self.len() { @@ -3761,6 +3814,16 @@ impl<T> [T] { /// assert!(v[i..].iter().all(|&x| !(x < 5))); /// ``` /// + /// If all elements of the slice match the predicate, including if the slice + /// is empty, then the length of the slice will be returned: + /// + /// ``` + /// let a = [2, 4, 8]; + /// assert_eq!(a.partition_point(|x| x < &100), a.len()); + /// let a: [i32; 0] = []; + /// assert_eq!(a.partition_point(|x| x < &100), 0); + /// ``` + /// /// If you want to insert an item to a sorted vector, while maintaining /// sort order: /// @@ -4051,7 +4114,7 @@ impl<T, const N: usize> [[T; N]] { /// ``` #[unstable(feature = "slice_flatten", issue = "95629")] pub fn flatten(&self) -> &[T] { - let len = if crate::mem::size_of::<T>() == 0 { + let len = if T::IS_ZST { self.len().checked_mul(N).expect("slice len overflow") } else { // SAFETY: `self.len() * N` cannot overflow because `self` is @@ -4089,7 +4152,7 @@ impl<T, const N: usize> [[T; N]] { /// ``` #[unstable(feature = "slice_flatten", issue = "95629")] pub fn flatten_mut(&mut self) -> &mut [T] { - let len = if crate::mem::size_of::<T>() == 0 { + let len = if T::IS_ZST { self.len().checked_mul(N).expect("slice len overflow") } else { // SAFETY: `self.len() * N` cannot overflow because `self` is @@ -4101,7 +4164,6 @@ impl<T, const N: usize> [[T; N]] { } } -#[cfg(not(bootstrap))] #[cfg(not(test))] impl [f32] { /// Sorts the slice of floats. @@ -4131,7 +4193,6 @@ impl [f32] { } } -#[cfg(not(bootstrap))] #[cfg(not(test))] impl [f64] { /// Sorts the slice of floats. diff --git a/library/core/src/slice/raw.rs b/library/core/src/slice/raw.rs index 107e71ab6..052fd34d0 100644 --- a/library/core/src/slice/raw.rs +++ b/library/core/src/slice/raw.rs @@ -1,7 +1,9 @@ //! Free functions to create `&[T]` and `&mut [T]`. use crate::array; -use crate::intrinsics::{assert_unsafe_precondition, is_aligned_and_not_null}; +use crate::intrinsics::{ + assert_unsafe_precondition, is_aligned_and_not_null, is_valid_allocation_size, +}; use crate::ops::Range; use crate::ptr; @@ -91,8 +93,9 @@ pub const unsafe fn from_raw_parts<'a, T>(data: *const T, len: usize) -> &'a [T] // SAFETY: the caller must uphold the safety contract for `from_raw_parts`. unsafe { assert_unsafe_precondition!( - is_aligned_and_not_null(data) - && crate::mem::size_of::<T>().saturating_mul(len) <= isize::MAX as usize + "slice::from_raw_parts requires the pointer to be aligned and non-null, and the total size of the slice not to exceed `isize::MAX`", + [T](data: *const T, len: usize) => is_aligned_and_not_null(data) + && is_valid_allocation_size::<T>(len) ); &*ptr::slice_from_raw_parts(data, len) } @@ -135,8 +138,9 @@ pub const unsafe fn from_raw_parts_mut<'a, T>(data: *mut T, len: usize) -> &'a m // SAFETY: the caller must uphold the safety contract for `from_raw_parts_mut`. unsafe { assert_unsafe_precondition!( - is_aligned_and_not_null(data) - && crate::mem::size_of::<T>().saturating_mul(len) <= isize::MAX as usize + "slice::from_raw_parts_mut requires the pointer to be aligned and non-null, and the total size of the slice not to exceed `isize::MAX`", + [T](data: *mut T, len: usize) => is_aligned_and_not_null(data) + && is_valid_allocation_size::<T>(len) ); &mut *ptr::slice_from_raw_parts_mut(data, len) } @@ -188,6 +192,10 @@ pub const fn from_mut<T>(s: &mut T) -> &mut [T] { /// /// Note that a range created from [`slice::as_ptr_range`] fulfills these requirements. /// +/// # Panics +/// +/// This function panics if `T` is a Zero-Sized Type (“ZST”). +/// /// # Caveat /// /// The lifetime for the returned slice is inferred from its usage. To @@ -219,9 +227,15 @@ pub const unsafe fn from_ptr_range<'a, T>(range: Range<*const T>) -> &'a [T] { unsafe { from_raw_parts(range.start, range.end.sub_ptr(range.start)) } } -/// Performs the same functionality as [`from_ptr_range`], except that a +/// Forms a mutable slice from a pointer range. +/// +/// This is the same functionality as [`from_ptr_range`], except that a /// mutable slice is returned. /// +/// This function is useful for interacting with foreign interfaces which +/// use two pointers to refer to a range of elements in memory, as is +/// common in C++. +/// /// # Safety /// /// Behavior is undefined if any of the following conditions are violated: @@ -247,6 +261,18 @@ pub const unsafe fn from_ptr_range<'a, T>(range: Range<*const T>) -> &'a [T] { /// /// Note that a range created from [`slice::as_mut_ptr_range`] fulfills these requirements. /// +/// # Panics +/// +/// This function panics if `T` is a Zero-Sized Type (“ZST”). +/// +/// # Caveat +/// +/// The lifetime for the returned slice is inferred from its usage. To +/// prevent accidental misuse, it's suggested to tie the lifetime to whichever +/// source lifetime is safe in the context, such as by providing a helper +/// function taking the lifetime of a host value for the slice, or by explicit +/// annotation. +/// /// # Examples /// /// ``` diff --git a/library/core/src/slice/rotate.rs b/library/core/src/slice/rotate.rs index 4589c6c0f..fa8c238f8 100644 --- a/library/core/src/slice/rotate.rs +++ b/library/core/src/slice/rotate.rs @@ -1,5 +1,5 @@ use crate::cmp; -use crate::mem::{self, MaybeUninit}; +use crate::mem::{self, MaybeUninit, SizedTypeProperties}; use crate::ptr; /// Rotates the range `[mid-left, mid+right)` such that the element at `mid` becomes the first @@ -63,7 +63,7 @@ use crate::ptr; /// when `left < right` the swapping happens from the left instead. pub unsafe fn ptr_rotate<T>(mut left: usize, mut mid: *mut T, mut right: usize) { type BufType = [usize; 32]; - if mem::size_of::<T>() == 0 { + if T::IS_ZST { return; } loop { diff --git a/library/core/src/slice/sort.rs b/library/core/src/slice/sort.rs index 6a201834b..87f77b7f2 100644 --- a/library/core/src/slice/sort.rs +++ b/library/core/src/slice/sort.rs @@ -7,7 +7,7 @@ //! stable sorting implementation. use crate::cmp; -use crate::mem::{self, MaybeUninit}; +use crate::mem::{self, MaybeUninit, SizedTypeProperties}; use crate::ptr; /// When dropped, copies from `src` into `dest`. @@ -326,8 +326,8 @@ where unsafe { // Branchless comparison. *end_l = i as u8; - end_l = end_l.offset(!is_less(&*elem, pivot) as isize); - elem = elem.offset(1); + end_l = end_l.add(!is_less(&*elem, pivot) as usize); + elem = elem.add(1); } } } @@ -352,9 +352,9 @@ where // Plus, `block_r` was asserted to be less than `BLOCK` and `elem` will therefore at most be pointing to the beginning of the slice. unsafe { // Branchless comparison. - elem = elem.offset(-1); + elem = elem.sub(1); *end_r = i as u8; - end_r = end_r.offset(is_less(&*elem, pivot) as isize); + end_r = end_r.add(is_less(&*elem, pivot) as usize); } } } @@ -365,12 +365,12 @@ where if count > 0 { macro_rules! left { () => { - l.offset(*start_l as isize) + l.add(usize::from(*start_l)) }; } macro_rules! right { () => { - r.offset(-(*start_r as isize) - 1) + r.sub(usize::from(*start_r) + 1) }; } @@ -398,16 +398,16 @@ where ptr::copy_nonoverlapping(right!(), left!(), 1); for _ in 1..count { - start_l = start_l.offset(1); + start_l = start_l.add(1); ptr::copy_nonoverlapping(left!(), right!(), 1); - start_r = start_r.offset(1); + start_r = start_r.add(1); ptr::copy_nonoverlapping(right!(), left!(), 1); } ptr::copy_nonoverlapping(&tmp, right!(), 1); mem::forget(tmp); - start_l = start_l.offset(1); - start_r = start_r.offset(1); + start_l = start_l.add(1); + start_r = start_r.add(1); } } @@ -420,7 +420,7 @@ where // safe. Otherwise, the debug assertions in the `is_done` case guarantee that // `width(l, r) == block_l + block_r`, namely, that the block sizes have been adjusted to account // for the smaller number of remaining elements. - l = unsafe { l.offset(block_l as isize) }; + l = unsafe { l.add(block_l) }; } if start_r == end_r { @@ -428,7 +428,7 @@ where // SAFETY: Same argument as [block-width-guarantee]. Either this is a full block `2*BLOCK`-wide, // or `block_r` has been adjusted for the last handful of elements. - r = unsafe { r.offset(-(block_r as isize)) }; + r = unsafe { r.sub(block_r) }; } if is_done { @@ -457,9 +457,9 @@ where // - `offsets_l` contains valid offsets into `v` collected during the partitioning of // the last block, so the `l.offset` calls are valid. unsafe { - end_l = end_l.offset(-1); - ptr::swap(l.offset(*end_l as isize), r.offset(-1)); - r = r.offset(-1); + end_l = end_l.sub(1); + ptr::swap(l.add(usize::from(*end_l)), r.sub(1)); + r = r.sub(1); } } width(v.as_mut_ptr(), r) @@ -470,9 +470,9 @@ where while start_r < end_r { // SAFETY: See the reasoning in [remaining-elements-safety]. unsafe { - end_r = end_r.offset(-1); - ptr::swap(l, r.offset(-(*end_r as isize) - 1)); - l = l.offset(1); + end_r = end_r.sub(1); + ptr::swap(l, r.sub(usize::from(*end_r) + 1)); + l = l.add(1); } } width(v.as_mut_ptr(), l) @@ -813,7 +813,7 @@ where F: FnMut(&T, &T) -> bool, { // Sorting has no meaningful behavior on zero-sized types. - if mem::size_of::<T>() == 0 { + if T::IS_ZST { return; } @@ -898,7 +898,7 @@ where panic!("partition_at_index index {} greater than length of slice {}", index, v.len()); } - if mem::size_of::<T>() == 0 { + if T::IS_ZST { // Sorting has no meaningful behavior on zero-sized types. Do nothing. } else if index == v.len() - 1 { // Find max element and place it in the last position of the array. We're free to use diff --git a/library/core/src/str/error.rs b/library/core/src/str/error.rs index 4e569fcc8..a11b5add4 100644 --- a/library/core/src/str/error.rs +++ b/library/core/src/str/error.rs @@ -1,5 +1,6 @@ //! Defines utf8 error type. +use crate::error::Error; use crate::fmt; /// Errors which can occur when attempting to interpret a sequence of [`u8`] @@ -122,6 +123,14 @@ impl fmt::Display for Utf8Error { } } +#[stable(feature = "rust1", since = "1.0.0")] +impl Error for Utf8Error { + #[allow(deprecated)] + fn description(&self) -> &str { + "invalid utf-8: corrupt contents" + } +} + /// An error returned when parsing a `bool` using [`from_str`] fails /// /// [`from_str`]: super::FromStr::from_str @@ -136,3 +145,11 @@ impl fmt::Display for ParseBoolError { "provided string was not `true` or `false`".fmt(f) } } + +#[stable(feature = "rust1", since = "1.0.0")] +impl Error for ParseBoolError { + #[allow(deprecated)] + fn description(&self) -> &str { + "failed to parse bool" + } +} diff --git a/library/core/src/str/lossy.rs b/library/core/src/str/lossy.rs index 6ec1c9390..59f873d12 100644 --- a/library/core/src/str/lossy.rs +++ b/library/core/src/str/lossy.rs @@ -1,51 +1,170 @@ -use crate::char; -use crate::fmt::{self, Write}; -use crate::mem; +use crate::fmt; +use crate::fmt::Formatter; +use crate::fmt::Write; +use crate::iter::FusedIterator; use super::from_utf8_unchecked; use super::validations::utf8_char_width; -/// Lossy UTF-8 string. -#[unstable(feature = "str_internals", issue = "none")] -pub struct Utf8Lossy { - bytes: [u8], +/// An item returned by the [`Utf8Chunks`] iterator. +/// +/// A `Utf8Chunk` stores a sequence of [`u8`] up to the first broken character +/// when decoding a UTF-8 string. +/// +/// # Examples +/// +/// ``` +/// #![feature(utf8_chunks)] +/// +/// use std::str::Utf8Chunks; +/// +/// // An invalid UTF-8 string +/// let bytes = b"foo\xF1\x80bar"; +/// +/// // Decode the first `Utf8Chunk` +/// let chunk = Utf8Chunks::new(bytes).next().unwrap(); +/// +/// // The first three characters are valid UTF-8 +/// assert_eq!("foo", chunk.valid()); +/// +/// // The fourth character is broken +/// assert_eq!(b"\xF1\x80", chunk.invalid()); +/// ``` +#[unstable(feature = "utf8_chunks", issue = "99543")] +#[derive(Clone, Debug, PartialEq, Eq)] +pub struct Utf8Chunk<'a> { + valid: &'a str, + invalid: &'a [u8], } -impl Utf8Lossy { +impl<'a> Utf8Chunk<'a> { + /// Returns the next validated UTF-8 substring. + /// + /// This substring can be empty at the start of the string or between + /// broken UTF-8 characters. #[must_use] - pub fn from_bytes(bytes: &[u8]) -> &Utf8Lossy { - // SAFETY: Both use the same memory layout, and UTF-8 correctness isn't required. - unsafe { mem::transmute(bytes) } + #[unstable(feature = "utf8_chunks", issue = "99543")] + pub fn valid(&self) -> &'a str { + self.valid } - pub fn chunks(&self) -> Utf8LossyChunksIter<'_> { - Utf8LossyChunksIter { source: &self.bytes } + /// Returns the invalid sequence that caused a failure. + /// + /// The returned slice will have a maximum length of 3 and starts after the + /// substring given by [`valid`]. Decoding will resume after this sequence. + /// + /// If empty, this is the last chunk in the string. If non-empty, an + /// unexpected byte was encountered or the end of the input was reached + /// unexpectedly. + /// + /// Lossy decoding would replace this sequence with [`U+FFFD REPLACEMENT + /// CHARACTER`]. + /// + /// [`valid`]: Self::valid + /// [`U+FFFD REPLACEMENT CHARACTER`]: crate::char::REPLACEMENT_CHARACTER + #[must_use] + #[unstable(feature = "utf8_chunks", issue = "99543")] + pub fn invalid(&self) -> &'a [u8] { + self.invalid } } -/// Iterator over lossy UTF-8 string -#[must_use = "iterators are lazy and do nothing unless consumed"] +#[must_use] +#[unstable(feature = "str_internals", issue = "none")] +pub struct Debug<'a>(&'a [u8]); + #[unstable(feature = "str_internals", issue = "none")] -#[allow(missing_debug_implementations)] -pub struct Utf8LossyChunksIter<'a> { +impl fmt::Debug for Debug<'_> { + fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result { + f.write_char('"')?; + + for chunk in Utf8Chunks::new(self.0) { + // Valid part. + // Here we partially parse UTF-8 again which is suboptimal. + { + let valid = chunk.valid(); + let mut from = 0; + for (i, c) in valid.char_indices() { + let esc = c.escape_debug(); + // If char needs escaping, flush backlog so far and write, else skip + if esc.len() != 1 { + f.write_str(&valid[from..i])?; + for c in esc { + f.write_char(c)?; + } + from = i + c.len_utf8(); + } + } + f.write_str(&valid[from..])?; + } + + // Broken parts of string as hex escape. + for &b in chunk.invalid() { + write!(f, "\\x{:02X}", b)?; + } + } + + f.write_char('"') + } +} + +/// An iterator used to decode a slice of mostly UTF-8 bytes to string slices +/// ([`&str`]) and byte slices ([`&[u8]`][byteslice]). +/// +/// If you want a simple conversion from UTF-8 byte slices to string slices, +/// [`from_utf8`] is easier to use. +/// +/// [byteslice]: slice +/// [`from_utf8`]: super::from_utf8 +/// +/// # Examples +/// +/// This can be used to create functionality similar to +/// [`String::from_utf8_lossy`] without allocating heap memory: +/// +/// ``` +/// #![feature(utf8_chunks)] +/// +/// use std::str::Utf8Chunks; +/// +/// fn from_utf8_lossy<F>(input: &[u8], mut push: F) where F: FnMut(&str) { +/// for chunk in Utf8Chunks::new(input) { +/// push(chunk.valid()); +/// +/// if !chunk.invalid().is_empty() { +/// push("\u{FFFD}"); +/// } +/// } +/// } +/// ``` +/// +/// [`String::from_utf8_lossy`]: ../../std/string/struct.String.html#method.from_utf8_lossy +#[must_use = "iterators are lazy and do nothing unless consumed"] +#[unstable(feature = "utf8_chunks", issue = "99543")] +#[derive(Clone)] +pub struct Utf8Chunks<'a> { source: &'a [u8], } -#[unstable(feature = "str_internals", issue = "none")] -#[derive(PartialEq, Eq, Debug)] -pub struct Utf8LossyChunk<'a> { - /// Sequence of valid chars. - /// Can be empty between broken UTF-8 chars. - pub valid: &'a str, - /// Single broken char, empty if none. - /// Empty iff iterator item is last. - pub broken: &'a [u8], +impl<'a> Utf8Chunks<'a> { + /// Creates a new iterator to decode the bytes. + #[unstable(feature = "utf8_chunks", issue = "99543")] + pub fn new(bytes: &'a [u8]) -> Self { + Self { source: bytes } + } + + #[doc(hidden)] + #[unstable(feature = "str_internals", issue = "none")] + pub fn debug(&self) -> Debug<'_> { + Debug(self.source) + } } -impl<'a> Iterator for Utf8LossyChunksIter<'a> { - type Item = Utf8LossyChunk<'a>; +#[unstable(feature = "utf8_chunks", issue = "99543")] +impl<'a> Iterator for Utf8Chunks<'a> { + type Item = Utf8Chunk<'a>; - fn next(&mut self) -> Option<Utf8LossyChunk<'a>> { + fn next(&mut self) -> Option<Utf8Chunk<'a>> { if self.source.is_empty() { return None; } @@ -130,71 +249,22 @@ impl<'a> Iterator for Utf8LossyChunksIter<'a> { // SAFETY: `valid_up_to <= i` because it is only ever assigned via // `valid_up_to = i` and `i` only increases. - let (valid, broken) = unsafe { inspected.split_at_unchecked(valid_up_to) }; + let (valid, invalid) = unsafe { inspected.split_at_unchecked(valid_up_to) }; - Some(Utf8LossyChunk { + Some(Utf8Chunk { // SAFETY: All bytes up to `valid_up_to` are valid UTF-8. valid: unsafe { from_utf8_unchecked(valid) }, - broken, + invalid, }) } } -impl fmt::Display for Utf8Lossy { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - // If we're the empty string then our iterator won't actually yield - // anything, so perform the formatting manually - if self.bytes.is_empty() { - return "".fmt(f); - } - - for Utf8LossyChunk { valid, broken } in self.chunks() { - // If we successfully decoded the whole chunk as a valid string then - // we can return a direct formatting of the string which will also - // respect various formatting flags if possible. - if valid.len() == self.bytes.len() { - assert!(broken.is_empty()); - return valid.fmt(f); - } - - f.write_str(valid)?; - if !broken.is_empty() { - f.write_char(char::REPLACEMENT_CHARACTER)?; - } - } - Ok(()) - } -} - -impl fmt::Debug for Utf8Lossy { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.write_char('"')?; +#[unstable(feature = "utf8_chunks", issue = "99543")] +impl FusedIterator for Utf8Chunks<'_> {} - for Utf8LossyChunk { valid, broken } in self.chunks() { - // Valid part. - // Here we partially parse UTF-8 again which is suboptimal. - { - let mut from = 0; - for (i, c) in valid.char_indices() { - let esc = c.escape_debug(); - // If char needs escaping, flush backlog so far and write, else skip - if esc.len() != 1 { - f.write_str(&valid[from..i])?; - for c in esc { - f.write_char(c)?; - } - from = i + c.len_utf8(); - } - } - f.write_str(&valid[from..])?; - } - - // Broken parts of string as hex escape. - for &b in broken { - write!(f, "\\x{:02x}", b)?; - } - } - - f.write_char('"') +#[unstable(feature = "utf8_chunks", issue = "99543")] +impl fmt::Debug for Utf8Chunks<'_> { + fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result { + f.debug_struct("Utf8Chunks").field("source", &self.debug()).finish() } } diff --git a/library/core/src/str/mod.rs b/library/core/src/str/mod.rs index c4f2e283e..fbc0fc397 100644 --- a/library/core/src/str/mod.rs +++ b/library/core/src/str/mod.rs @@ -22,9 +22,9 @@ use crate::slice::{self, SliceIndex}; pub mod pattern; -#[unstable(feature = "str_internals", issue = "none")] -#[allow(missing_docs)] -pub mod lossy; +mod lossy; +#[unstable(feature = "utf8_chunks", issue = "99543")] +pub use lossy::{Utf8Chunk, Utf8Chunks}; #[stable(feature = "rust1", since = "1.0.0")] pub use converts::{from_utf8, from_utf8_unchecked}; @@ -91,10 +91,12 @@ const fn slice_error_fail(s: &str, begin: usize, end: usize) -> ! { } } +#[track_caller] const fn slice_error_fail_ct(_: &str, _: usize, _: usize) -> ! { panic!("failed to slice string"); } +#[track_caller] fn slice_error_fail_rt(s: &str, begin: usize, end: usize) -> ! { const MAX_DISPLAY_LENGTH: usize = 256; let trunc_len = s.floor_char_boundary(MAX_DISPLAY_LENGTH); @@ -2353,7 +2355,7 @@ impl str { #[inline] pub fn is_ascii(&self) -> bool { // We can treat each byte as character here: all multibyte characters - // start with a byte that is not in the ascii range, so we will stop + // start with a byte that is not in the ASCII range, so we will stop // there already. self.as_bytes().is_ascii() } @@ -2638,3 +2640,6 @@ impl_fn_for_zst! { unsafe { from_utf8_unchecked(bytes) } }; } + +#[stable(feature = "rust1", since = "1.0.0")] +impl !crate::error::Error for &str {} diff --git a/library/core/src/str/pattern.rs b/library/core/src/str/pattern.rs index 031fb8e8b..ec2cb429e 100644 --- a/library/core/src/str/pattern.rs +++ b/library/core/src/str/pattern.rs @@ -267,7 +267,7 @@ pub unsafe trait Searcher<'a> { /// The index ranges returned by this trait are not required /// to exactly match those of the forward search in reverse. /// -/// For the reason why this trait is marked unsafe, see them +/// For the reason why this trait is marked unsafe, see the /// parent trait [`Searcher`]. pub unsafe trait ReverseSearcher<'a>: Searcher<'a> { /// Performs the next search step starting from the back. diff --git a/library/core/src/str/traits.rs b/library/core/src/str/traits.rs index e9649fc91..d3ed811b1 100644 --- a/library/core/src/str/traits.rs +++ b/library/core/src/str/traits.rs @@ -507,7 +507,6 @@ unsafe impl const SliceIndex<str> for ops::RangeToInclusive<usize> { /// /// ``` /// use std::str::FromStr; -/// use std::num::ParseIntError; /// /// #[derive(Debug, PartialEq)] /// struct Point { @@ -515,18 +514,21 @@ unsafe impl const SliceIndex<str> for ops::RangeToInclusive<usize> { /// y: i32 /// } /// +/// #[derive(Debug, PartialEq, Eq)] +/// struct ParsePointError; +/// /// impl FromStr for Point { -/// type Err = ParseIntError; +/// type Err = ParsePointError; /// /// fn from_str(s: &str) -> Result<Self, Self::Err> { /// let (x, y) = s /// .strip_prefix('(') /// .and_then(|s| s.strip_suffix(')')) /// .and_then(|s| s.split_once(',')) -/// .unwrap(); +/// .ok_or(ParsePointError)?; /// -/// let x_fromstr = x.parse::<i32>()?; -/// let y_fromstr = y.parse::<i32>()?; +/// let x_fromstr = x.parse::<i32>().map_err(|_| ParsePointError)?; +/// let y_fromstr = y.parse::<i32>().map_err(|_| ParsePointError)?; /// /// Ok(Point { x: x_fromstr, y: y_fromstr }) /// } @@ -538,6 +540,8 @@ unsafe impl const SliceIndex<str> for ops::RangeToInclusive<usize> { /// // Implicit calls, through parse /// assert_eq!("(1,2)".parse(), expected); /// assert_eq!("(1,2)".parse::<Point>(), expected); +/// // Invalid input string +/// assert!(Point::from_str("(1 2)").is_err()); /// ``` #[stable(feature = "rust1", since = "1.0.0")] pub trait FromStr: Sized { @@ -573,8 +577,8 @@ impl FromStr for bool { /// Parse a `bool` from a string. /// - /// Yields a `Result<bool, ParseBoolError>`, because `s` may or may not - /// actually be parseable. + /// The only accepted values are `"true"` and `"false"`. Any other input + /// will return an error. /// /// # Examples /// diff --git a/library/core/src/str/validations.rs b/library/core/src/str/validations.rs index 04bc66523..2acef432f 100644 --- a/library/core/src/str/validations.rs +++ b/library/core/src/str/validations.rs @@ -216,12 +216,12 @@ pub(super) const fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> { // SAFETY: since `align - index` and `ascii_block_size` are // multiples of `usize_bytes`, `block = ptr.add(index)` is // always aligned with a `usize` so it's safe to dereference - // both `block` and `block.offset(1)`. + // both `block` and `block.add(1)`. unsafe { let block = ptr.add(index) as *const usize; // break if there is a nonascii byte let zu = contains_nonascii(*block); - let zv = contains_nonascii(*block.offset(1)); + let zv = contains_nonascii(*block.add(1)); if zu || zv { break; } diff --git a/library/core/src/sync/atomic.rs b/library/core/src/sync/atomic.rs index 5e2e0c4d8..edc68d6fa 100644 --- a/library/core/src/sync/atomic.rs +++ b/library/core/src/sync/atomic.rs @@ -294,7 +294,7 @@ impl AtomicBool { /// ``` /// use std::sync::atomic::AtomicBool; /// - /// let atomic_true = AtomicBool::new(true); + /// let atomic_true = AtomicBool::new(true); /// let atomic_false = AtomicBool::new(false); /// ``` #[inline] @@ -955,6 +955,14 @@ impl AtomicBool { /// **Note:** This method is only available on platforms that support atomic /// operations on `u8`. /// + /// # Considerations + /// + /// This method is not magic; it is not provided by the hardware. + /// It is implemented in terms of [`AtomicBool::compare_exchange_weak`], and suffers from the same drawbacks. + /// In particular, this method will not circumvent the [ABA Problem]. + /// + /// [ABA Problem]: https://en.wikipedia.org/wiki/ABA_problem + /// /// # Examples /// /// ```rust @@ -1171,7 +1179,7 @@ impl<T> AtomicPtr<T> { /// use std::sync::atomic::{AtomicPtr, Ordering}; /// /// let ptr = &mut 5; - /// let some_ptr = AtomicPtr::new(ptr); + /// let some_ptr = AtomicPtr::new(ptr); /// /// let value = some_ptr.load(Ordering::Relaxed); /// ``` @@ -1198,7 +1206,7 @@ impl<T> AtomicPtr<T> { /// use std::sync::atomic::{AtomicPtr, Ordering}; /// /// let ptr = &mut 5; - /// let some_ptr = AtomicPtr::new(ptr); + /// let some_ptr = AtomicPtr::new(ptr); /// /// let other_ptr = &mut 10; /// @@ -1230,7 +1238,7 @@ impl<T> AtomicPtr<T> { /// use std::sync::atomic::{AtomicPtr, Ordering}; /// /// let ptr = &mut 5; - /// let some_ptr = AtomicPtr::new(ptr); + /// let some_ptr = AtomicPtr::new(ptr); /// /// let other_ptr = &mut 10; /// @@ -1282,9 +1290,9 @@ impl<T> AtomicPtr<T> { /// use std::sync::atomic::{AtomicPtr, Ordering}; /// /// let ptr = &mut 5; - /// let some_ptr = AtomicPtr::new(ptr); + /// let some_ptr = AtomicPtr::new(ptr); /// - /// let other_ptr = &mut 10; + /// let other_ptr = &mut 10; /// /// let value = some_ptr.compare_and_swap(ptr, other_ptr, Ordering::Relaxed); /// ``` @@ -1325,9 +1333,9 @@ impl<T> AtomicPtr<T> { /// use std::sync::atomic::{AtomicPtr, Ordering}; /// /// let ptr = &mut 5; - /// let some_ptr = AtomicPtr::new(ptr); + /// let some_ptr = AtomicPtr::new(ptr); /// - /// let other_ptr = &mut 10; + /// let other_ptr = &mut 10; /// /// let value = some_ptr.compare_exchange(ptr, other_ptr, /// Ordering::SeqCst, Ordering::Relaxed); @@ -1422,6 +1430,14 @@ impl<T> AtomicPtr<T> { /// **Note:** This method is only available on platforms that support atomic /// operations on pointers. /// + /// # Considerations + /// + /// This method is not magic; it is not provided by the hardware. + /// It is implemented in terms of [`AtomicPtr::compare_exchange_weak`], and suffers from the same drawbacks. + /// In particular, this method will not circumvent the [ABA Problem]. + /// + /// [ABA Problem]: https://en.wikipedia.org/wiki/ABA_problem + /// /// # Examples /// /// ```rust @@ -1554,8 +1570,8 @@ impl<T> AtomicPtr<T> { /// Offsets the pointer's address by adding `val` *bytes*, returning the /// previous pointer. /// - /// This is equivalent to using [`wrapping_add`] and [`cast`] to atomically - /// perform `ptr = ptr.cast::<u8>().wrapping_add(val).cast::<T>()`. + /// This is equivalent to using [`wrapping_byte_add`] to atomically + /// perform `ptr = ptr.wrapping_byte_add(val)`. /// /// `fetch_byte_add` takes an [`Ordering`] argument which describes the /// memory ordering of this operation. All ordering modes are possible. Note @@ -1565,8 +1581,7 @@ impl<T> AtomicPtr<T> { /// **Note**: This method is only available on platforms that support atomic /// operations on [`AtomicPtr`]. /// - /// [`wrapping_add`]: pointer::wrapping_add - /// [`cast`]: pointer::cast + /// [`wrapping_byte_add`]: pointer::wrapping_byte_add /// /// # Examples /// @@ -1584,23 +1599,15 @@ impl<T> AtomicPtr<T> { #[unstable(feature = "strict_provenance_atomic_ptr", issue = "99108")] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub fn fetch_byte_add(&self, val: usize, order: Ordering) -> *mut T { - #[cfg(not(bootstrap))] - // SAFETY: data races are prevented by atomic intrinsics. - unsafe { - atomic_add(self.p.get(), core::ptr::invalid_mut(val), order).cast() - } - #[cfg(bootstrap)] // SAFETY: data races are prevented by atomic intrinsics. - unsafe { - atomic_add(self.p.get().cast::<usize>(), val, order) as *mut T - } + unsafe { atomic_add(self.p.get(), core::ptr::invalid_mut(val), order).cast() } } /// Offsets the pointer's address by subtracting `val` *bytes*, returning the /// previous pointer. /// - /// This is equivalent to using [`wrapping_sub`] and [`cast`] to atomically - /// perform `ptr = ptr.cast::<u8>().wrapping_sub(val).cast::<T>()`. + /// This is equivalent to using [`wrapping_byte_sub`] to atomically + /// perform `ptr = ptr.wrapping_byte_sub(val)`. /// /// `fetch_byte_sub` takes an [`Ordering`] argument which describes the /// memory ordering of this operation. All ordering modes are possible. Note @@ -1610,8 +1617,7 @@ impl<T> AtomicPtr<T> { /// **Note**: This method is only available on platforms that support atomic /// operations on [`AtomicPtr`]. /// - /// [`wrapping_sub`]: pointer::wrapping_sub - /// [`cast`]: pointer::cast + /// [`wrapping_byte_sub`]: pointer::wrapping_byte_sub /// /// # Examples /// @@ -1628,24 +1634,16 @@ impl<T> AtomicPtr<T> { #[unstable(feature = "strict_provenance_atomic_ptr", issue = "99108")] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub fn fetch_byte_sub(&self, val: usize, order: Ordering) -> *mut T { - #[cfg(not(bootstrap))] // SAFETY: data races are prevented by atomic intrinsics. - unsafe { - atomic_sub(self.p.get(), core::ptr::invalid_mut(val), order).cast() - } - #[cfg(bootstrap)] - // SAFETY: data races are prevented by atomic intrinsics. - unsafe { - atomic_sub(self.p.get().cast::<usize>(), val, order) as *mut T - } + unsafe { atomic_sub(self.p.get(), core::ptr::invalid_mut(val), order).cast() } } /// Performs a bitwise "or" operation on the address of the current pointer, /// and the argument `val`, and stores a pointer with provenance of the /// current pointer and the resulting address. /// - /// This is equivalent equivalent to using [`map_addr`] to atomically - /// perform `ptr = ptr.map_addr(|a| a | val)`. This can be used in tagged + /// This is equivalent to using [`map_addr`] to atomically perform + /// `ptr = ptr.map_addr(|a| a | val)`. This can be used in tagged /// pointer schemes to atomically set tag bits. /// /// **Caveat**: This operation returns the previous value. To compute the @@ -1687,24 +1685,16 @@ impl<T> AtomicPtr<T> { #[unstable(feature = "strict_provenance_atomic_ptr", issue = "99108")] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub fn fetch_or(&self, val: usize, order: Ordering) -> *mut T { - #[cfg(not(bootstrap))] - // SAFETY: data races are prevented by atomic intrinsics. - unsafe { - atomic_or(self.p.get(), core::ptr::invalid_mut(val), order).cast() - } - #[cfg(bootstrap)] // SAFETY: data races are prevented by atomic intrinsics. - unsafe { - atomic_or(self.p.get().cast::<usize>(), val, order) as *mut T - } + unsafe { atomic_or(self.p.get(), core::ptr::invalid_mut(val), order).cast() } } /// Performs a bitwise "and" operation on the address of the current /// pointer, and the argument `val`, and stores a pointer with provenance of /// the current pointer and the resulting address. /// - /// This is equivalent equivalent to using [`map_addr`] to atomically - /// perform `ptr = ptr.map_addr(|a| a & val)`. This can be used in tagged + /// This is equivalent to using [`map_addr`] to atomically perform + /// `ptr = ptr.map_addr(|a| a & val)`. This can be used in tagged /// pointer schemes to atomically unset tag bits. /// /// **Caveat**: This operation returns the previous value. To compute the @@ -1745,24 +1735,16 @@ impl<T> AtomicPtr<T> { #[unstable(feature = "strict_provenance_atomic_ptr", issue = "99108")] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub fn fetch_and(&self, val: usize, order: Ordering) -> *mut T { - #[cfg(not(bootstrap))] - // SAFETY: data races are prevented by atomic intrinsics. - unsafe { - atomic_and(self.p.get(), core::ptr::invalid_mut(val), order).cast() - } - #[cfg(bootstrap)] // SAFETY: data races are prevented by atomic intrinsics. - unsafe { - atomic_and(self.p.get().cast::<usize>(), val, order) as *mut T - } + unsafe { atomic_and(self.p.get(), core::ptr::invalid_mut(val), order).cast() } } /// Performs a bitwise "xor" operation on the address of the current /// pointer, and the argument `val`, and stores a pointer with provenance of /// the current pointer and the resulting address. /// - /// This is equivalent equivalent to using [`map_addr`] to atomically - /// perform `ptr = ptr.map_addr(|a| a ^ val)`. This can be used in tagged + /// This is equivalent to using [`map_addr`] to atomically perform + /// `ptr = ptr.map_addr(|a| a ^ val)`. This can be used in tagged /// pointer schemes to atomically toggle tag bits. /// /// **Caveat**: This operation returns the previous value. To compute the @@ -1801,16 +1783,8 @@ impl<T> AtomicPtr<T> { #[unstable(feature = "strict_provenance_atomic_ptr", issue = "99108")] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub fn fetch_xor(&self, val: usize, order: Ordering) -> *mut T { - #[cfg(not(bootstrap))] - // SAFETY: data races are prevented by atomic intrinsics. - unsafe { - atomic_xor(self.p.get(), core::ptr::invalid_mut(val), order).cast() - } - #[cfg(bootstrap)] // SAFETY: data races are prevented by atomic intrinsics. - unsafe { - atomic_xor(self.p.get().cast::<usize>(), val, order) as *mut T - } + unsafe { atomic_xor(self.p.get(), core::ptr::invalid_mut(val), order).cast() } } } @@ -2552,6 +2526,16 @@ macro_rules! atomic_int { /// **Note**: This method is only available on platforms that support atomic operations on #[doc = concat!("[`", $s_int_type, "`].")] /// + /// # Considerations + /// + /// This method is not magic; it is not provided by the hardware. + /// It is implemented in terms of + #[doc = concat!("[`", stringify!($atomic_type), "::compare_exchange_weak`],")] + /// and suffers from the same drawbacks. + /// In particular, this method will not circumvent the [ABA Problem]. + /// + /// [ABA Problem]: https://en.wikipedia.org/wiki/ABA_problem + /// /// # Examples /// /// ```rust @@ -3073,30 +3057,22 @@ unsafe fn atomic_compare_exchange<T: Copy>( let (val, ok) = unsafe { match (success, failure) { (Relaxed, Relaxed) => intrinsics::atomic_cxchg_relaxed_relaxed(dst, old, new), - #[cfg(not(bootstrap))] (Relaxed, Acquire) => intrinsics::atomic_cxchg_relaxed_acquire(dst, old, new), - #[cfg(not(bootstrap))] (Relaxed, SeqCst) => intrinsics::atomic_cxchg_relaxed_seqcst(dst, old, new), (Acquire, Relaxed) => intrinsics::atomic_cxchg_acquire_relaxed(dst, old, new), (Acquire, Acquire) => intrinsics::atomic_cxchg_acquire_acquire(dst, old, new), - #[cfg(not(bootstrap))] (Acquire, SeqCst) => intrinsics::atomic_cxchg_acquire_seqcst(dst, old, new), (Release, Relaxed) => intrinsics::atomic_cxchg_release_relaxed(dst, old, new), - #[cfg(not(bootstrap))] (Release, Acquire) => intrinsics::atomic_cxchg_release_acquire(dst, old, new), - #[cfg(not(bootstrap))] (Release, SeqCst) => intrinsics::atomic_cxchg_release_seqcst(dst, old, new), (AcqRel, Relaxed) => intrinsics::atomic_cxchg_acqrel_relaxed(dst, old, new), (AcqRel, Acquire) => intrinsics::atomic_cxchg_acqrel_acquire(dst, old, new), - #[cfg(not(bootstrap))] (AcqRel, SeqCst) => intrinsics::atomic_cxchg_acqrel_seqcst(dst, old, new), (SeqCst, Relaxed) => intrinsics::atomic_cxchg_seqcst_relaxed(dst, old, new), (SeqCst, Acquire) => intrinsics::atomic_cxchg_seqcst_acquire(dst, old, new), (SeqCst, SeqCst) => intrinsics::atomic_cxchg_seqcst_seqcst(dst, old, new), (_, AcqRel) => panic!("there is no such thing as an acquire-release failure ordering"), (_, Release) => panic!("there is no such thing as a release failure ordering"), - #[cfg(bootstrap)] - _ => panic!("a failure ordering can't be stronger than a success ordering"), } }; if ok { Ok(val) } else { Err(val) } @@ -3116,30 +3092,22 @@ unsafe fn atomic_compare_exchange_weak<T: Copy>( let (val, ok) = unsafe { match (success, failure) { (Relaxed, Relaxed) => intrinsics::atomic_cxchgweak_relaxed_relaxed(dst, old, new), - #[cfg(not(bootstrap))] (Relaxed, Acquire) => intrinsics::atomic_cxchgweak_relaxed_acquire(dst, old, new), - #[cfg(not(bootstrap))] (Relaxed, SeqCst) => intrinsics::atomic_cxchgweak_relaxed_seqcst(dst, old, new), (Acquire, Relaxed) => intrinsics::atomic_cxchgweak_acquire_relaxed(dst, old, new), (Acquire, Acquire) => intrinsics::atomic_cxchgweak_acquire_acquire(dst, old, new), - #[cfg(not(bootstrap))] (Acquire, SeqCst) => intrinsics::atomic_cxchgweak_acquire_seqcst(dst, old, new), (Release, Relaxed) => intrinsics::atomic_cxchgweak_release_relaxed(dst, old, new), - #[cfg(not(bootstrap))] (Release, Acquire) => intrinsics::atomic_cxchgweak_release_acquire(dst, old, new), - #[cfg(not(bootstrap))] (Release, SeqCst) => intrinsics::atomic_cxchgweak_release_seqcst(dst, old, new), (AcqRel, Relaxed) => intrinsics::atomic_cxchgweak_acqrel_relaxed(dst, old, new), (AcqRel, Acquire) => intrinsics::atomic_cxchgweak_acqrel_acquire(dst, old, new), - #[cfg(not(bootstrap))] (AcqRel, SeqCst) => intrinsics::atomic_cxchgweak_acqrel_seqcst(dst, old, new), (SeqCst, Relaxed) => intrinsics::atomic_cxchgweak_seqcst_relaxed(dst, old, new), (SeqCst, Acquire) => intrinsics::atomic_cxchgweak_seqcst_acquire(dst, old, new), (SeqCst, SeqCst) => intrinsics::atomic_cxchgweak_seqcst_seqcst(dst, old, new), (_, AcqRel) => panic!("there is no such thing as an acquire-release failure ordering"), (_, Release) => panic!("there is no such thing as a release failure ordering"), - #[cfg(bootstrap)] - _ => panic!("a failure ordering can't be stronger than a success ordering"), } }; if ok { Ok(val) } else { Err(val) } diff --git a/library/core/src/sync/exclusive.rs b/library/core/src/sync/exclusive.rs index a7519ab5a..c65c27500 100644 --- a/library/core/src/sync/exclusive.rs +++ b/library/core/src/sync/exclusive.rs @@ -100,6 +100,7 @@ impl<T: Sized> Exclusive<T> { /// Wrap a value in an `Exclusive` #[unstable(feature = "exclusive_wrapper", issue = "98407")] #[must_use] + #[inline] pub const fn new(t: T) -> Self { Self { inner: t } } @@ -107,6 +108,7 @@ impl<T: Sized> Exclusive<T> { /// Unwrap the value contained in the `Exclusive` #[unstable(feature = "exclusive_wrapper", issue = "98407")] #[must_use] + #[inline] pub const fn into_inner(self) -> T { self.inner } @@ -116,6 +118,7 @@ impl<T: ?Sized> Exclusive<T> { /// Get exclusive access to the underlying value. #[unstable(feature = "exclusive_wrapper", issue = "98407")] #[must_use] + #[inline] pub const fn get_mut(&mut self) -> &mut T { &mut self.inner } @@ -128,6 +131,7 @@ impl<T: ?Sized> Exclusive<T> { /// produce _pinned_ access to the underlying value. #[unstable(feature = "exclusive_wrapper", issue = "98407")] #[must_use] + #[inline] pub const fn get_pin_mut(self: Pin<&mut Self>) -> Pin<&mut T> { // SAFETY: `Exclusive` can only produce `&mut T` if itself is unpinned // `Pin::map_unchecked_mut` is not const, so we do this conversion manually @@ -139,6 +143,7 @@ impl<T: ?Sized> Exclusive<T> { /// building an `Exclusive` with [`Exclusive::new`]. #[unstable(feature = "exclusive_wrapper", issue = "98407")] #[must_use] + #[inline] pub const fn from_mut(r: &'_ mut T) -> &'_ mut Exclusive<T> { // SAFETY: repr is ≥ C, so refs have the same layout; and `Exclusive` properties are `&mut`-agnostic unsafe { &mut *(r as *mut T as *mut Exclusive<T>) } @@ -149,6 +154,7 @@ impl<T: ?Sized> Exclusive<T> { /// building an `Exclusive` with [`Exclusive::new`]. #[unstable(feature = "exclusive_wrapper", issue = "98407")] #[must_use] + #[inline] pub const fn from_pin_mut(r: Pin<&'_ mut T>) -> Pin<&'_ mut Exclusive<T>> { // SAFETY: `Exclusive` can only produce `&mut T` if itself is unpinned // `Pin::map_unchecked_mut` is not const, so we do this conversion manually @@ -158,6 +164,7 @@ impl<T: ?Sized> Exclusive<T> { #[unstable(feature = "exclusive_wrapper", issue = "98407")] impl<T> From<T> for Exclusive<T> { + #[inline] fn from(t: T) -> Self { Self::new(t) } @@ -166,7 +173,7 @@ impl<T> From<T> for Exclusive<T> { #[unstable(feature = "exclusive_wrapper", issue = "98407")] impl<T: Future + ?Sized> Future for Exclusive<T> { type Output = T::Output; - + #[inline] fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> { self.get_pin_mut().poll(cx) } diff --git a/library/core/src/task/wake.rs b/library/core/src/task/wake.rs index 87d4a25af..0cff972df 100644 --- a/library/core/src/task/wake.rs +++ b/library/core/src/task/wake.rs @@ -71,6 +71,12 @@ impl RawWaker { /// pointer of a properly constructed [`RawWaker`] object from inside the /// [`RawWaker`] implementation. Calling one of the contained functions using /// any other `data` pointer will cause undefined behavior. +/// +/// These functions must all be thread-safe (even though [`RawWaker`] is +/// <code>\![Send] + \![Sync]</code>) +/// because [`Waker`] is <code>[Send] + [Sync]</code>, and thus wakers may be moved to +/// arbitrary threads or invoked by `&` reference. For example, this means that if the +/// `clone` and `drop` functions manage a reference count, they must do so atomically. #[stable(feature = "futures_api", since = "1.36.0")] #[derive(PartialEq, Copy, Clone, Debug)] pub struct RawWakerVTable { @@ -110,6 +116,12 @@ impl RawWakerVTable { /// Creates a new `RawWakerVTable` from the provided `clone`, `wake`, /// `wake_by_ref`, and `drop` functions. /// + /// These functions must all be thread-safe (even though [`RawWaker`] is + /// <code>\![Send] + \![Sync]</code>) + /// because [`Waker`] is <code>[Send] + [Sync]</code>, and thus wakers may be moved to + /// arbitrary threads or invoked by `&` reference. For example, this means that if the + /// `clone` and `drop` functions manage a reference count, they must do so atomically. + /// /// # `clone` /// /// This function will be called when the [`RawWaker`] gets cloned, e.g. when @@ -157,9 +169,9 @@ impl RawWakerVTable { } } -/// The `Context` of an asynchronous task. +/// The context of an asynchronous task. /// -/// Currently, `Context` only serves to provide access to a `&Waker` +/// Currently, `Context` only serves to provide access to a [`&Waker`](Waker) /// which can be used to wake the current task. #[stable(feature = "futures_api", since = "1.36.0")] pub struct Context<'a> { @@ -172,19 +184,21 @@ pub struct Context<'a> { } impl<'a> Context<'a> { - /// Create a new `Context` from a `&Waker`. + /// Create a new `Context` from a [`&Waker`](Waker). #[stable(feature = "futures_api", since = "1.36.0")] + #[rustc_const_unstable(feature = "const_waker", issue = "102012")] #[must_use] #[inline] - pub fn from_waker(waker: &'a Waker) -> Self { + pub const fn from_waker(waker: &'a Waker) -> Self { Context { waker, _marker: PhantomData } } - /// Returns a reference to the `Waker` for the current task. + /// Returns a reference to the [`Waker`] for the current task. #[stable(feature = "futures_api", since = "1.36.0")] + #[rustc_const_unstable(feature = "const_waker", issue = "102012")] #[must_use] #[inline] - pub fn waker(&self) -> &'a Waker { + pub const fn waker(&self) -> &'a Waker { &self.waker } } @@ -202,7 +216,18 @@ impl fmt::Debug for Context<'_> { /// This handle encapsulates a [`RawWaker`] instance, which defines the /// executor-specific wakeup behavior. /// -/// Implements [`Clone`], [`Send`], and [`Sync`]. +/// The typical life of a `Waker` is that it is constructed by an executor, wrapped in a +/// [`Context`], then passed to [`Future::poll()`]. Then, if the future chooses to return +/// [`Poll::Pending`], it must also store the waker somehow and call [`Waker::wake()`] when +/// the future should be polled again. +/// +/// Implements [`Clone`], [`Send`], and [`Sync`]; therefore, a waker may be invoked +/// from any thread, including ones not in any way managed by the executor. For example, +/// this might be done to wake a future when a blocking function call completes on another +/// thread. +/// +/// [`Future::poll()`]: core::future::Future::poll +/// [`Poll::Pending`]: core::task::Poll::Pending #[repr(transparent)] #[stable(feature = "futures_api", since = "1.36.0")] pub struct Waker { @@ -219,18 +244,21 @@ unsafe impl Sync for Waker {} impl Waker { /// Wake up the task associated with this `Waker`. /// - /// As long as the runtime keeps running and the task is not finished, it is - /// guaranteed that each invocation of `wake` (or `wake_by_ref`) will be followed - /// by at least one `poll` of the task to which this `Waker` belongs. This makes + /// As long as the executor keeps running and the task is not finished, it is + /// guaranteed that each invocation of [`wake()`](Self::wake) (or + /// [`wake_by_ref()`](Self::wake_by_ref)) will be followed by at least one + /// [`poll()`] of the task to which this `Waker` belongs. This makes /// it possible to temporarily yield to other tasks while running potentially /// unbounded processing loops. /// /// Note that the above implies that multiple wake-ups may be coalesced into a - /// single `poll` invocation by the runtime. + /// single [`poll()`] invocation by the runtime. /// /// Also note that yielding to competing tasks is not guaranteed: it is the /// executor’s choice which task to run and the executor may choose to run the /// current task again. + /// + /// [`poll()`]: crate::future::Future::poll #[inline] #[stable(feature = "futures_api", since = "1.36.0")] pub fn wake(self) { @@ -250,8 +278,8 @@ impl Waker { /// Wake up the task associated with this `Waker` without consuming the `Waker`. /// - /// This is similar to `wake`, but may be slightly less efficient in the case - /// where an owned `Waker` is available. This method should be preferred to + /// This is similar to [`wake()`](Self::wake), but may be slightly less efficient in + /// the case where an owned `Waker` is available. This method should be preferred to /// calling `waker.clone().wake()`. #[inline] #[stable(feature = "futures_api", since = "1.36.0")] @@ -263,7 +291,7 @@ impl Waker { unsafe { (self.waker.vtable.wake_by_ref)(self.waker.data) } } - /// Returns `true` if this `Waker` and another `Waker` have awoken the same task. + /// Returns `true` if this `Waker` and another `Waker` would awake the same task. /// /// This function works on a best-effort basis, and may return false even /// when the `Waker`s would awaken the same task. However, if this function @@ -285,7 +313,8 @@ impl Waker { #[inline] #[must_use] #[stable(feature = "futures_api", since = "1.36.0")] - pub unsafe fn from_raw(waker: RawWaker) -> Waker { + #[rustc_const_unstable(feature = "const_waker", issue = "102012")] + pub const unsafe fn from_raw(waker: RawWaker) -> Waker { Waker { waker } } diff --git a/library/core/src/time.rs b/library/core/src/time.rs index 756f1a166..ba1cb6efa 100644 --- a/library/core/src/time.rs +++ b/library/core/src/time.rs @@ -29,6 +29,20 @@ const NANOS_PER_MICRO: u32 = 1_000; const MILLIS_PER_SEC: u64 = 1_000; const MICROS_PER_SEC: u64 = 1_000_000; +#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] +#[repr(transparent)] +#[rustc_layout_scalar_valid_range_start(0)] +#[rustc_layout_scalar_valid_range_end(999_999_999)] +struct Nanoseconds(u32); + +impl Default for Nanoseconds { + #[inline] + fn default() -> Self { + // SAFETY: 0 is within the valid range + unsafe { Nanoseconds(0) } + } +} + /// A `Duration` type to represent a span of time, typically used for system /// timeouts. /// @@ -71,7 +85,7 @@ const MICROS_PER_SEC: u64 = 1_000_000; #[cfg_attr(not(test), rustc_diagnostic_item = "Duration")] pub struct Duration { secs: u64, - nanos: u32, // Always 0 <= nanos < NANOS_PER_SEC + nanos: Nanoseconds, // Always 0 <= nanos < NANOS_PER_SEC } impl Duration { @@ -188,7 +202,8 @@ impl Duration { None => panic!("overflow in Duration::new"), }; let nanos = nanos % NANOS_PER_SEC; - Duration { secs, nanos } + // SAFETY: nanos % NANOS_PER_SEC < NANOS_PER_SEC, therefore nanos is within the valid range + Duration { secs, nanos: unsafe { Nanoseconds(nanos) } } } /// Creates a new `Duration` from the specified number of whole seconds. @@ -208,7 +223,7 @@ impl Duration { #[inline] #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")] pub const fn from_secs(secs: u64) -> Duration { - Duration { secs, nanos: 0 } + Duration::new(secs, 0) } /// Creates a new `Duration` from the specified number of milliseconds. @@ -228,10 +243,7 @@ impl Duration { #[inline] #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")] pub const fn from_millis(millis: u64) -> Duration { - Duration { - secs: millis / MILLIS_PER_SEC, - nanos: ((millis % MILLIS_PER_SEC) as u32) * NANOS_PER_MILLI, - } + Duration::new(millis / MILLIS_PER_SEC, ((millis % MILLIS_PER_SEC) as u32) * NANOS_PER_MILLI) } /// Creates a new `Duration` from the specified number of microseconds. @@ -251,10 +263,7 @@ impl Duration { #[inline] #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")] pub const fn from_micros(micros: u64) -> Duration { - Duration { - secs: micros / MICROS_PER_SEC, - nanos: ((micros % MICROS_PER_SEC) as u32) * NANOS_PER_MICRO, - } + Duration::new(micros / MICROS_PER_SEC, ((micros % MICROS_PER_SEC) as u32) * NANOS_PER_MICRO) } /// Creates a new `Duration` from the specified number of nanoseconds. @@ -274,10 +283,7 @@ impl Duration { #[inline] #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")] pub const fn from_nanos(nanos: u64) -> Duration { - Duration { - secs: nanos / (NANOS_PER_SEC as u64), - nanos: (nanos % (NANOS_PER_SEC as u64)) as u32, - } + Duration::new(nanos / (NANOS_PER_SEC as u64), (nanos % (NANOS_PER_SEC as u64)) as u32) } /// Returns true if this `Duration` spans no time. @@ -301,7 +307,7 @@ impl Duration { #[rustc_const_stable(feature = "duration_zero", since = "1.53.0")] #[inline] pub const fn is_zero(&self) -> bool { - self.secs == 0 && self.nanos == 0 + self.secs == 0 && self.nanos.0 == 0 } /// Returns the number of _whole_ seconds contained by this `Duration`. @@ -318,19 +324,11 @@ impl Duration { /// assert_eq!(duration.as_secs(), 5); /// ``` /// - /// To determine the total number of seconds represented by the `Duration`, - /// use `as_secs` in combination with [`subsec_nanos`]: - /// - /// ``` - /// use std::time::Duration; - /// - /// let duration = Duration::new(5, 730023852); - /// - /// assert_eq!(5.730023852, - /// duration.as_secs() as f64 - /// + duration.subsec_nanos() as f64 * 1e-9); - /// ``` + /// To determine the total number of seconds represented by the `Duration` + /// including the fractional part, use [`as_secs_f64`] or [`as_secs_f32`] /// + /// [`as_secs_f64`]: Duration::as_secs_f64 + /// [`as_secs_f32`]: Duration::as_secs_f32 /// [`subsec_nanos`]: Duration::subsec_nanos #[stable(feature = "duration", since = "1.3.0")] #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")] @@ -360,7 +358,7 @@ impl Duration { #[must_use] #[inline] pub const fn subsec_millis(&self) -> u32 { - self.nanos / NANOS_PER_MILLI + self.nanos.0 / NANOS_PER_MILLI } /// Returns the fractional part of this `Duration`, in whole microseconds. @@ -383,7 +381,7 @@ impl Duration { #[must_use] #[inline] pub const fn subsec_micros(&self) -> u32 { - self.nanos / NANOS_PER_MICRO + self.nanos.0 / NANOS_PER_MICRO } /// Returns the fractional part of this `Duration`, in nanoseconds. @@ -406,7 +404,7 @@ impl Duration { #[must_use] #[inline] pub const fn subsec_nanos(&self) -> u32 { - self.nanos + self.nanos.0 } /// Returns the total number of whole milliseconds contained by this `Duration`. @@ -424,7 +422,7 @@ impl Duration { #[must_use] #[inline] pub const fn as_millis(&self) -> u128 { - self.secs as u128 * MILLIS_PER_SEC as u128 + (self.nanos / NANOS_PER_MILLI) as u128 + self.secs as u128 * MILLIS_PER_SEC as u128 + (self.nanos.0 / NANOS_PER_MILLI) as u128 } /// Returns the total number of whole microseconds contained by this `Duration`. @@ -442,7 +440,7 @@ impl Duration { #[must_use] #[inline] pub const fn as_micros(&self) -> u128 { - self.secs as u128 * MICROS_PER_SEC as u128 + (self.nanos / NANOS_PER_MICRO) as u128 + self.secs as u128 * MICROS_PER_SEC as u128 + (self.nanos.0 / NANOS_PER_MICRO) as u128 } /// Returns the total number of nanoseconds contained by this `Duration`. @@ -460,7 +458,7 @@ impl Duration { #[must_use] #[inline] pub const fn as_nanos(&self) -> u128 { - self.secs as u128 * NANOS_PER_SEC as u128 + self.nanos as u128 + self.secs as u128 * NANOS_PER_SEC as u128 + self.nanos.0 as u128 } /// Checked `Duration` addition. Computes `self + other`, returning [`None`] @@ -483,7 +481,7 @@ impl Duration { #[rustc_const_stable(feature = "duration_consts_2", since = "1.58.0")] pub const fn checked_add(self, rhs: Duration) -> Option<Duration> { if let Some(mut secs) = self.secs.checked_add(rhs.secs) { - let mut nanos = self.nanos + rhs.nanos; + let mut nanos = self.nanos.0 + rhs.nanos.0; if nanos >= NANOS_PER_SEC { nanos -= NANOS_PER_SEC; if let Some(new_secs) = secs.checked_add(1) { @@ -493,7 +491,7 @@ impl Duration { } } debug_assert!(nanos < NANOS_PER_SEC); - Some(Duration { secs, nanos }) + Some(Duration::new(secs, nanos)) } else { None } @@ -543,16 +541,16 @@ impl Duration { #[rustc_const_stable(feature = "duration_consts_2", since = "1.58.0")] pub const fn checked_sub(self, rhs: Duration) -> Option<Duration> { if let Some(mut secs) = self.secs.checked_sub(rhs.secs) { - let nanos = if self.nanos >= rhs.nanos { - self.nanos - rhs.nanos + let nanos = if self.nanos.0 >= rhs.nanos.0 { + self.nanos.0 - rhs.nanos.0 } else if let Some(sub_secs) = secs.checked_sub(1) { secs = sub_secs; - self.nanos + NANOS_PER_SEC - rhs.nanos + self.nanos.0 + NANOS_PER_SEC - rhs.nanos.0 } else { return None; }; debug_assert!(nanos < NANOS_PER_SEC); - Some(Duration { secs, nanos }) + Some(Duration::new(secs, nanos)) } else { None } @@ -601,13 +599,13 @@ impl Duration { #[rustc_const_stable(feature = "duration_consts_2", since = "1.58.0")] pub const fn checked_mul(self, rhs: u32) -> Option<Duration> { // Multiply nanoseconds as u64, because it cannot overflow that way. - let total_nanos = self.nanos as u64 * rhs as u64; + let total_nanos = self.nanos.0 as u64 * rhs as u64; let extra_secs = total_nanos / (NANOS_PER_SEC as u64); let nanos = (total_nanos % (NANOS_PER_SEC as u64)) as u32; if let Some(s) = self.secs.checked_mul(rhs as u64) { if let Some(secs) = s.checked_add(extra_secs) { debug_assert!(nanos < NANOS_PER_SEC); - return Some(Duration { secs, nanos }); + return Some(Duration::new(secs, nanos)); } } None @@ -661,9 +659,9 @@ impl Duration { let secs = self.secs / (rhs as u64); let carry = self.secs - secs * (rhs as u64); let extra_nanos = carry * (NANOS_PER_SEC as u64) / (rhs as u64); - let nanos = self.nanos / rhs + (extra_nanos as u32); + let nanos = self.nanos.0 / rhs + (extra_nanos as u32); debug_assert!(nanos < NANOS_PER_SEC); - Some(Duration { secs, nanos }) + Some(Duration::new(secs, nanos)) } else { None } @@ -685,7 +683,7 @@ impl Duration { #[inline] #[rustc_const_unstable(feature = "duration_consts_float", issue = "72440")] pub const fn as_secs_f64(&self) -> f64 { - (self.secs as f64) + (self.nanos as f64) / (NANOS_PER_SEC as f64) + (self.secs as f64) + (self.nanos.0 as f64) / (NANOS_PER_SEC as f64) } /// Returns the number of seconds contained by this `Duration` as `f32`. @@ -704,7 +702,7 @@ impl Duration { #[inline] #[rustc_const_unstable(feature = "duration_consts_float", issue = "72440")] pub const fn as_secs_f32(&self) -> f32 { - (self.secs as f32) + (self.nanos as f32) / (NANOS_PER_SEC as f32) + (self.secs as f32) + (self.nanos.0 as f32) / (NANOS_PER_SEC as f32) } /// Creates a new `Duration` from the specified number of seconds represented @@ -995,13 +993,13 @@ macro_rules! sum_durations { for entry in $iter { total_secs = total_secs.checked_add(entry.secs).expect("overflow in iter::sum over durations"); - total_nanos = match total_nanos.checked_add(entry.nanos as u64) { + total_nanos = match total_nanos.checked_add(entry.nanos.0 as u64) { Some(n) => n, None => { total_secs = total_secs .checked_add(total_nanos / NANOS_PER_SEC as u64) .expect("overflow in iter::sum over durations"); - (total_nanos % NANOS_PER_SEC as u64) + entry.nanos as u64 + (total_nanos % NANOS_PER_SEC as u64) + entry.nanos.0 as u64 } }; } @@ -1009,7 +1007,7 @@ macro_rules! sum_durations { .checked_add(total_nanos / NANOS_PER_SEC as u64) .expect("overflow in iter::sum over durations"); total_nanos = total_nanos % NANOS_PER_SEC as u64; - Duration { secs: total_secs, nanos: total_nanos as u32 } + Duration::new(total_secs, total_nanos as u32) }}; } @@ -1045,7 +1043,7 @@ impl fmt::Debug for Duration { /// to the formatter's `width`, if specified. fn fmt_decimal( f: &mut fmt::Formatter<'_>, - mut integer_part: u64, + integer_part: u64, mut fractional_part: u32, mut divisor: u32, prefix: &str, @@ -1077,7 +1075,7 @@ impl fmt::Debug for Duration { // normal floating point numbers. However, we only need to do work // when rounding up. This happens if the first digit of the // remaining ones is >= 5. - if fractional_part > 0 && fractional_part >= divisor * 5 { + let integer_part = if fractional_part > 0 && fractional_part >= divisor * 5 { // Round up the number contained in the buffer. We go through // the buffer backwards and keep track of the carry. let mut rev_pos = pos; @@ -1101,9 +1099,18 @@ impl fmt::Debug for Duration { // the whole buffer to '0's and need to increment the integer // part. if carry { - integer_part += 1; + // If `integer_part == u64::MAX` and precision < 9, any + // carry of the overflow during rounding of the + // `fractional_part` into the `integer_part` will cause the + // `integer_part` itself to overflow. Avoid this by using an + // `Option<u64>`, with `None` representing `u64::MAX + 1`. + integer_part.checked_add(1) + } else { + Some(integer_part) } - } + } else { + Some(integer_part) + }; // Determine the end of the buffer: if precision is set, we just // use as many digits from the buffer (capped to 9). If it isn't @@ -1113,7 +1120,12 @@ impl fmt::Debug for Duration { // This closure emits the formatted duration without emitting any // padding (padding is calculated below). let emit_without_padding = |f: &mut fmt::Formatter<'_>| { - write!(f, "{}{}", prefix, integer_part)?; + if let Some(integer_part) = integer_part { + write!(f, "{}{}", prefix, integer_part)?; + } else { + // u64::MAX + 1 == 18446744073709551616 + write!(f, "{}18446744073709551616", prefix)?; + } // Write the decimal point and the fractional part (if any). if end > 0 { @@ -1143,12 +1155,17 @@ impl fmt::Debug for Duration { // 2. The postfix: can be "µs" so we have to count UTF8 characters. let mut actual_w = prefix.len() + postfix.chars().count(); // 3. The integer part: - if let Some(log) = integer_part.checked_log10() { - // integer_part is > 0, so has length log10(x)+1 - actual_w += 1 + log as usize; + if let Some(integer_part) = integer_part { + if let Some(log) = integer_part.checked_ilog10() { + // integer_part is > 0, so has length log10(x)+1 + actual_w += 1 + log as usize; + } else { + // integer_part is 0, so has length 1. + actual_w += 1; + } } else { - // integer_part is 0, so has length 1. - actual_w += 1; + // integer_part is u64::MAX + 1, so has length 20 + actual_w += 20; } // 4. The fractional part (if any): if end > 0 { @@ -1174,27 +1191,27 @@ impl fmt::Debug for Duration { let prefix = if f.sign_plus() { "+" } else { "" }; if self.secs > 0 { - fmt_decimal(f, self.secs, self.nanos, NANOS_PER_SEC / 10, prefix, "s") - } else if self.nanos >= NANOS_PER_MILLI { + fmt_decimal(f, self.secs, self.nanos.0, NANOS_PER_SEC / 10, prefix, "s") + } else if self.nanos.0 >= NANOS_PER_MILLI { fmt_decimal( f, - (self.nanos / NANOS_PER_MILLI) as u64, - self.nanos % NANOS_PER_MILLI, + (self.nanos.0 / NANOS_PER_MILLI) as u64, + self.nanos.0 % NANOS_PER_MILLI, NANOS_PER_MILLI / 10, prefix, "ms", ) - } else if self.nanos >= NANOS_PER_MICRO { + } else if self.nanos.0 >= NANOS_PER_MICRO { fmt_decimal( f, - (self.nanos / NANOS_PER_MICRO) as u64, - self.nanos % NANOS_PER_MICRO, + (self.nanos.0 / NANOS_PER_MICRO) as u64, + self.nanos.0 % NANOS_PER_MICRO, NANOS_PER_MICRO / 10, prefix, "µs", ) } else { - fmt_decimal(f, self.nanos as u64, 0, 1, prefix, "ns") + fmt_decimal(f, self.nanos.0 as u64, 0, 1, prefix, "ns") } } } @@ -1208,7 +1225,6 @@ impl fmt::Debug for Duration { /// # Example /// /// ``` -/// #![feature(duration_checked_float)] /// use std::time::Duration; /// /// if let Err(e) = Duration::try_from_secs_f32(-1.0) { @@ -1216,33 +1232,33 @@ impl fmt::Debug for Duration { /// } /// ``` #[derive(Debug, Clone, PartialEq, Eq)] -#[unstable(feature = "duration_checked_float", issue = "83400")] -pub struct FromFloatSecsError { - kind: FromFloatSecsErrorKind, +#[stable(feature = "duration_checked_float", since = "1.66.0")] +pub struct TryFromFloatSecsError { + kind: TryFromFloatSecsErrorKind, } -impl FromFloatSecsError { +impl TryFromFloatSecsError { const fn description(&self) -> &'static str { match self.kind { - FromFloatSecsErrorKind::Negative => { + TryFromFloatSecsErrorKind::Negative => { "can not convert float seconds to Duration: value is negative" } - FromFloatSecsErrorKind::OverflowOrNan => { + TryFromFloatSecsErrorKind::OverflowOrNan => { "can not convert float seconds to Duration: value is either too big or NaN" } } } } -#[unstable(feature = "duration_checked_float", issue = "83400")] -impl fmt::Display for FromFloatSecsError { +#[stable(feature = "duration_checked_float", since = "1.66.0")] +impl fmt::Display for TryFromFloatSecsError { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { self.description().fmt(f) } } #[derive(Debug, Clone, PartialEq, Eq)] -enum FromFloatSecsErrorKind { +enum TryFromFloatSecsErrorKind { // Value is negative. Negative, // Value is either too big to be represented as `Duration` or `NaN`. @@ -1262,8 +1278,8 @@ macro_rules! try_from_secs { const MANT_MASK: $bits_ty = (1 << $mant_bits) - 1; const EXP_MASK: $bits_ty = (1 << $exp_bits) - 1; - if $secs.is_sign_negative() { - return Err(FromFloatSecsError { kind: FromFloatSecsErrorKind::Negative }); + if $secs < 0.0 { + return Err(TryFromFloatSecsError { kind: TryFromFloatSecsErrorKind::Negative }); } let bits = $secs.to_bits(); @@ -1288,7 +1304,7 @@ macro_rules! try_from_secs { let rem_msb = nanos_tmp & rem_msb_mask == 0; let add_ns = !(rem_msb || (is_even && is_tie)); - // f32 does not have enough presicion to trigger the second branch + // f32 does not have enough precision to trigger the second branch // since it can not represent numbers between 0.999_999_940_395 and 1.0. let nanos = nanos + add_ns as u32; if ($mant_bits == 23) || (nanos != NANOS_PER_SEC) { (0, nanos) } else { (1, 0) } @@ -1307,9 +1323,9 @@ macro_rules! try_from_secs { let rem_msb = nanos_tmp & rem_msb_mask == 0; let add_ns = !(rem_msb || (is_even && is_tie)); - // f32 does not have enough presicion to trigger the second branch. + // f32 does not have enough precision to trigger the second branch. // For example, it can not represent numbers between 1.999_999_880... - // and 2.0. Bigger values result in even smaller presicion of the + // and 2.0. Bigger values result in even smaller precision of the // fractional part. let nanos = nanos + add_ns as u32; if ($mant_bits == 23) || (nanos != NANOS_PER_SEC) { @@ -1322,10 +1338,10 @@ macro_rules! try_from_secs { let secs = u64::from(mant) << (exp - $mant_bits); (secs, 0) } else { - return Err(FromFloatSecsError { kind: FromFloatSecsErrorKind::OverflowOrNan }); + return Err(TryFromFloatSecsError { kind: TryFromFloatSecsErrorKind::OverflowOrNan }); }; - Ok(Duration { secs, nanos }) + Ok(Duration::new(secs, nanos)) }}; } @@ -1338,8 +1354,6 @@ impl Duration { /// /// # Examples /// ``` - /// #![feature(duration_checked_float)] - /// /// use std::time::Duration; /// /// let res = Duration::try_from_secs_f32(0.0); @@ -1387,9 +1401,10 @@ impl Duration { /// let res = Duration::try_from_secs_f32(val); /// assert_eq!(res, Ok(Duration::new(1, 2_929_688))); /// ``` - #[unstable(feature = "duration_checked_float", issue = "83400")] + #[stable(feature = "duration_checked_float", since = "1.66.0")] + #[rustc_const_unstable(feature = "duration_consts_float", issue = "72440")] #[inline] - pub const fn try_from_secs_f32(secs: f32) -> Result<Duration, FromFloatSecsError> { + pub const fn try_from_secs_f32(secs: f32) -> Result<Duration, TryFromFloatSecsError> { try_from_secs!( secs = secs, mantissa_bits = 23, @@ -1408,8 +1423,6 @@ impl Duration { /// /// # Examples /// ``` - /// #![feature(duration_checked_float)] - /// /// use std::time::Duration; /// /// let res = Duration::try_from_secs_f64(0.0); @@ -1465,9 +1478,10 @@ impl Duration { /// let res = Duration::try_from_secs_f64(val); /// assert_eq!(res, Ok(Duration::new(1, 2_929_688))); /// ``` - #[unstable(feature = "duration_checked_float", issue = "83400")] + #[stable(feature = "duration_checked_float", since = "1.66.0")] + #[rustc_const_unstable(feature = "duration_consts_float", issue = "72440")] #[inline] - pub const fn try_from_secs_f64(secs: f64) -> Result<Duration, FromFloatSecsError> { + pub const fn try_from_secs_f64(secs: f64) -> Result<Duration, TryFromFloatSecsError> { try_from_secs!( secs = secs, mantissa_bits = 52, diff --git a/library/core/src/tuple.rs b/library/core/src/tuple.rs index d189e6400..fc91fe468 100644 --- a/library/core/src/tuple.rs +++ b/library/core/src/tuple.rs @@ -93,7 +93,8 @@ macro_rules! tuple_impls { maybe_tuple_doc! { $($T)+ @ #[stable(feature = "rust1", since = "1.0.0")] - impl<$($T:Default),+> Default for ($($T,)+) { + #[rustc_const_unstable(feature = "const_default_impls", issue = "87864")] + impl<$($T: ~const Default),+> const Default for ($($T,)+) { #[inline] fn default() -> ($($T,)+) { ($({ let x: $T = Default::default(); x},)+) @@ -107,7 +108,7 @@ macro_rules! tuple_impls { // Otherwise, it hides the docs entirely. macro_rules! maybe_tuple_doc { ($a:ident @ #[$meta:meta] $item:item) => { - #[cfg_attr(not(bootstrap), doc(fake_variadic))] + #[doc(fake_variadic)] #[doc = "This trait is implemented for tuples up to twelve items long."] #[$meta] $item diff --git a/library/core/src/unicode/printable.rs b/library/core/src/unicode/printable.rs index 31cf88a41..ffb18a5ba 100644 --- a/library/core/src/unicode/printable.rs +++ b/library/core/src/unicode/printable.rs @@ -54,7 +54,7 @@ pub(crate) fn is_printable(x: char) -> bool { if 0x2a6e0 <= x && x < 0x2a700 { return false; } - if 0x2b739 <= x && x < 0x2b740 { + if 0x2b73a <= x && x < 0x2b740 { return false; } if 0x2b81e <= x && x < 0x2b820 { @@ -69,7 +69,10 @@ pub(crate) fn is_printable(x: char) -> bool { if 0x2fa1e <= x && x < 0x30000 { return false; } - if 0x3134b <= x && x < 0xe0100 { + if 0x3134b <= x && x < 0x31350 { + return false; + } + if 0x323b0 <= x && x < 0xe0100 { return false; } if 0xe01f0 <= x && x < 0x110000 { @@ -92,7 +95,7 @@ const SINGLETONS0U: &[(u8, u8)] = &[ (0x0b, 25), (0x0c, 26), (0x0d, 16), - (0x0e, 13), + (0x0e, 12), (0x0f, 4), (0x10, 3), (0x12, 18), @@ -142,24 +145,24 @@ const SINGLETONS0L: &[u8] = &[ 0xe4, 0xe5, 0xf0, 0x0d, 0x11, 0x45, 0x49, 0x64, 0x65, 0x80, 0x84, 0xb2, 0xbc, 0xbe, 0xbf, 0xd5, 0xd7, 0xf0, 0xf1, 0x83, 0x85, 0x8b, 0xa4, 0xa6, - 0xbe, 0xbf, 0xc5, 0xc7, 0xce, 0xcf, 0xda, 0xdb, - 0x48, 0x98, 0xbd, 0xcd, 0xc6, 0xce, 0xcf, 0x49, - 0x4e, 0x4f, 0x57, 0x59, 0x5e, 0x5f, 0x89, 0x8e, - 0x8f, 0xb1, 0xb6, 0xb7, 0xbf, 0xc1, 0xc6, 0xc7, - 0xd7, 0x11, 0x16, 0x17, 0x5b, 0x5c, 0xf6, 0xf7, - 0xfe, 0xff, 0x80, 0x6d, 0x71, 0xde, 0xdf, 0x0e, - 0x1f, 0x6e, 0x6f, 0x1c, 0x1d, 0x5f, 0x7d, 0x7e, - 0xae, 0xaf, 0x7f, 0xbb, 0xbc, 0x16, 0x17, 0x1e, - 0x1f, 0x46, 0x47, 0x4e, 0x4f, 0x58, 0x5a, 0x5c, - 0x5e, 0x7e, 0x7f, 0xb5, 0xc5, 0xd4, 0xd5, 0xdc, - 0xf0, 0xf1, 0xf5, 0x72, 0x73, 0x8f, 0x74, 0x75, - 0x96, 0x26, 0x2e, 0x2f, 0xa7, 0xaf, 0xb7, 0xbf, - 0xc7, 0xcf, 0xd7, 0xdf, 0x9a, 0x40, 0x97, 0x98, - 0x30, 0x8f, 0x1f, 0xd2, 0xd4, 0xce, 0xff, 0x4e, - 0x4f, 0x5a, 0x5b, 0x07, 0x08, 0x0f, 0x10, 0x27, - 0x2f, 0xee, 0xef, 0x6e, 0x6f, 0x37, 0x3d, 0x3f, - 0x42, 0x45, 0x90, 0x91, 0x53, 0x67, 0x75, 0xc8, - 0xc9, 0xd0, 0xd1, 0xd8, 0xd9, 0xe7, 0xfe, 0xff, + 0xbe, 0xbf, 0xc5, 0xc7, 0xcf, 0xda, 0xdb, 0x48, + 0x98, 0xbd, 0xcd, 0xc6, 0xce, 0xcf, 0x49, 0x4e, + 0x4f, 0x57, 0x59, 0x5e, 0x5f, 0x89, 0x8e, 0x8f, + 0xb1, 0xb6, 0xb7, 0xbf, 0xc1, 0xc6, 0xc7, 0xd7, + 0x11, 0x16, 0x17, 0x5b, 0x5c, 0xf6, 0xf7, 0xfe, + 0xff, 0x80, 0x6d, 0x71, 0xde, 0xdf, 0x0e, 0x1f, + 0x6e, 0x6f, 0x1c, 0x1d, 0x5f, 0x7d, 0x7e, 0xae, + 0xaf, 0x7f, 0xbb, 0xbc, 0x16, 0x17, 0x1e, 0x1f, + 0x46, 0x47, 0x4e, 0x4f, 0x58, 0x5a, 0x5c, 0x5e, + 0x7e, 0x7f, 0xb5, 0xc5, 0xd4, 0xd5, 0xdc, 0xf0, + 0xf1, 0xf5, 0x72, 0x73, 0x8f, 0x74, 0x75, 0x96, + 0x26, 0x2e, 0x2f, 0xa7, 0xaf, 0xb7, 0xbf, 0xc7, + 0xcf, 0xd7, 0xdf, 0x9a, 0x40, 0x97, 0x98, 0x30, + 0x8f, 0x1f, 0xd2, 0xd4, 0xce, 0xff, 0x4e, 0x4f, + 0x5a, 0x5b, 0x07, 0x08, 0x0f, 0x10, 0x27, 0x2f, + 0xee, 0xef, 0x6e, 0x6f, 0x37, 0x3d, 0x3f, 0x42, + 0x45, 0x90, 0x91, 0x53, 0x67, 0x75, 0xc8, 0xc9, + 0xd0, 0xd1, 0xd8, 0xd9, 0xe7, 0xfe, 0xff, ]; #[rustfmt::skip] const SINGLETONS1U: &[(u8, u8)] = &[ @@ -184,10 +187,12 @@ const SINGLETONS1U: &[(u8, u8)] = &[ (0x19, 13), (0x1c, 5), (0x1d, 8), + (0x1f, 1), (0x24, 1), (0x6a, 4), (0x6b, 2), (0xaf, 3), + (0xb1, 2), (0xbc, 2), (0xcf, 2), (0xd1, 2), @@ -203,7 +208,7 @@ const SINGLETONS1U: &[(u8, u8)] = &[ (0xee, 32), (0xf0, 4), (0xf8, 2), - (0xfa, 2), + (0xfa, 3), (0xfb, 1), ]; #[rustfmt::skip] @@ -220,18 +225,19 @@ const SINGLETONS1L: &[u8] = &[ 0x0a, 0x0b, 0x14, 0x17, 0x36, 0x39, 0x3a, 0xa8, 0xa9, 0xd8, 0xd9, 0x09, 0x37, 0x90, 0x91, 0xa8, 0x07, 0x0a, 0x3b, 0x3e, 0x66, 0x69, 0x8f, 0x92, - 0x6f, 0x5f, 0xbf, 0xee, 0xef, 0x5a, 0x62, 0xf4, - 0xfc, 0xff, 0x9a, 0x9b, 0x2e, 0x2f, 0x27, 0x28, - 0x55, 0x9d, 0xa0, 0xa1, 0xa3, 0xa4, 0xa7, 0xa8, - 0xad, 0xba, 0xbc, 0xc4, 0x06, 0x0b, 0x0c, 0x15, - 0x1d, 0x3a, 0x3f, 0x45, 0x51, 0xa6, 0xa7, 0xcc, - 0xcd, 0xa0, 0x07, 0x19, 0x1a, 0x22, 0x25, 0x3e, - 0x3f, 0xe7, 0xec, 0xef, 0xff, 0xc5, 0xc6, 0x04, - 0x20, 0x23, 0x25, 0x26, 0x28, 0x33, 0x38, 0x3a, - 0x48, 0x4a, 0x4c, 0x50, 0x53, 0x55, 0x56, 0x58, - 0x5a, 0x5c, 0x5e, 0x60, 0x63, 0x65, 0x66, 0x6b, - 0x73, 0x78, 0x7d, 0x7f, 0x8a, 0xa4, 0xaa, 0xaf, - 0xb0, 0xc0, 0xd0, 0xae, 0xaf, 0x6e, 0x6f, 0x93, + 0x11, 0x6f, 0x5f, 0xbf, 0xee, 0xef, 0x5a, 0x62, + 0xf4, 0xfc, 0xff, 0x53, 0x54, 0x9a, 0x9b, 0x2e, + 0x2f, 0x27, 0x28, 0x55, 0x9d, 0xa0, 0xa1, 0xa3, + 0xa4, 0xa7, 0xa8, 0xad, 0xba, 0xbc, 0xc4, 0x06, + 0x0b, 0x0c, 0x15, 0x1d, 0x3a, 0x3f, 0x45, 0x51, + 0xa6, 0xa7, 0xcc, 0xcd, 0xa0, 0x07, 0x19, 0x1a, + 0x22, 0x25, 0x3e, 0x3f, 0xe7, 0xec, 0xef, 0xff, + 0xc5, 0xc6, 0x04, 0x20, 0x23, 0x25, 0x26, 0x28, + 0x33, 0x38, 0x3a, 0x48, 0x4a, 0x4c, 0x50, 0x53, + 0x55, 0x56, 0x58, 0x5a, 0x5c, 0x5e, 0x60, 0x63, + 0x65, 0x66, 0x6b, 0x73, 0x78, 0x7d, 0x7f, 0x8a, + 0xa4, 0xaa, 0xaf, 0xb0, 0xc0, 0xd0, 0xae, 0xaf, + 0x6e, 0x6f, 0xbe, 0x93, ]; #[rustfmt::skip] const NORMAL0: &[u8] = &[ @@ -272,7 +278,7 @@ const NORMAL0: &[u8] = &[ 0x1b, 0x07, 0x57, 0x07, 0x02, 0x06, - 0x16, 0x0d, + 0x17, 0x0c, 0x50, 0x04, 0x43, 0x03, 0x2d, 0x03, @@ -424,8 +430,8 @@ const NORMAL1: &[u8] = &[ 0x33, 0x07, 0x2e, 0x08, 0x0a, 0x81, 0x26, - 0x52, 0x4e, - 0x28, 0x08, + 0x52, 0x4b, + 0x2b, 0x08, 0x2a, 0x16, 0x1a, 0x26, 0x1c, 0x14, @@ -438,7 +444,7 @@ const NORMAL1: &[u8] = &[ 0x48, 0x08, 0x27, 0x09, 0x75, 0x0b, - 0x3f, 0x41, + 0x42, 0x3e, 0x2a, 0x06, 0x3b, 0x05, 0x0a, 0x06, @@ -464,7 +470,8 @@ const NORMAL1: &[u8] = &[ 0x45, 0x1b, 0x48, 0x08, 0x53, 0x0d, - 0x49, 0x81, 0x07, + 0x49, 0x07, + 0x0a, 0x80, 0xf6, 0x46, 0x0a, 0x1d, 0x03, 0x47, 0x49, @@ -473,14 +480,17 @@ const NORMAL1: &[u8] = &[ 0x0a, 0x06, 0x39, 0x07, 0x0a, 0x81, 0x36, - 0x19, 0x80, 0xb7, + 0x19, 0x07, + 0x3b, 0x03, + 0x1c, 0x56, 0x01, 0x0f, 0x32, 0x0d, 0x83, 0x9b, 0x66, 0x75, 0x0b, 0x80, 0xc4, 0x8a, 0x4c, 0x63, 0x0d, - 0x84, 0x2f, 0x8f, 0xd1, + 0x84, 0x30, 0x10, + 0x16, 0x8f, 0xaa, 0x82, 0x47, 0xa1, 0xb9, 0x82, 0x39, 0x07, 0x2a, 0x04, @@ -498,8 +508,9 @@ const NORMAL1: &[u8] = &[ 0x97, 0xf8, 0x08, 0x84, 0xd6, 0x2a, 0x09, 0xa2, 0xe7, - 0x81, 0x33, 0x2d, - 0x03, 0x11, + 0x81, 0x33, 0x0f, + 0x01, 0x1d, + 0x06, 0x0e, 0x04, 0x08, 0x81, 0x8c, 0x89, 0x04, 0x6b, 0x05, @@ -511,21 +522,26 @@ const NORMAL1: &[u8] = &[ 0x80, 0xf6, 0x0a, 0x73, 0x08, 0x70, 0x15, - 0x46, 0x80, 0x9a, + 0x46, 0x7a, + 0x14, 0x0c, 0x14, 0x0c, 0x57, 0x09, 0x19, 0x80, 0x87, 0x81, 0x47, 0x03, 0x85, 0x42, 0x0f, 0x15, 0x84, 0x50, - 0x1f, 0x80, 0xe1, - 0x2b, 0x80, 0xd5, + 0x1f, 0x06, + 0x06, 0x80, 0xd5, + 0x2b, 0x05, + 0x3e, 0x21, + 0x01, 0x70, 0x2d, 0x03, 0x1a, 0x04, 0x02, 0x81, 0x40, 0x1f, 0x11, 0x3a, 0x05, - 0x01, 0x84, 0xe0, + 0x01, 0x81, 0xd0, + 0x2a, 0x82, 0xe6, 0x80, 0xf7, 0x29, 0x4c, 0x04, 0x0a, 0x04, @@ -546,11 +562,11 @@ const NORMAL1: &[u8] = &[ 0x09, 0x07, 0x02, 0x0e, 0x06, 0x80, 0x9a, - 0x83, 0xd8, 0x05, - 0x10, 0x03, + 0x83, 0xd8, 0x04, + 0x11, 0x03, 0x0d, 0x03, - 0x74, 0x0c, - 0x59, 0x07, + 0x77, 0x04, + 0x5f, 0x06, 0x0c, 0x04, 0x01, 0x0f, 0x0c, 0x04, @@ -559,15 +575,12 @@ const NORMAL1: &[u8] = &[ 0x28, 0x08, 0x22, 0x4e, 0x81, 0x54, 0x0c, - 0x15, 0x03, - 0x05, 0x03, - 0x07, 0x09, 0x1d, 0x03, - 0x0b, 0x05, - 0x06, 0x0a, - 0x0a, 0x06, - 0x08, 0x08, - 0x07, 0x09, + 0x09, 0x07, + 0x36, 0x08, + 0x0e, 0x04, + 0x09, 0x07, + 0x09, 0x07, 0x80, 0xcb, 0x25, 0x0a, 0x84, 0x06, ]; diff --git a/library/core/src/unicode/unicode_data.rs b/library/core/src/unicode/unicode_data.rs index d2073f86c..bd69ca520 100644 --- a/library/core/src/unicode/unicode_data.rs +++ b/library/core/src/unicode/unicode_data.rs @@ -1,7 +1,8 @@ ///! This file is generated by src/tools/unicode-table-generator; do not edit manually! +#[rustc_const_unstable(feature = "const_unicode_case_lookup", issue = "101400")] #[inline(always)] -fn bitset_search< +const fn bitset_search< const N: usize, const CHUNK_SIZE: usize, const N1: usize, @@ -17,14 +18,18 @@ fn bitset_search< let bucket_idx = (needle / 64) as usize; let chunk_map_idx = bucket_idx / CHUNK_SIZE; let chunk_piece = bucket_idx % CHUNK_SIZE; - let chunk_idx = if let Some(&v) = chunk_idx_map.get(chunk_map_idx) { - v + // FIXME: const-hack: Revert to `slice::get` after `const_slice_index` + // feature stabilizes. + let chunk_idx = if chunk_map_idx < chunk_idx_map.len() { + chunk_idx_map[chunk_map_idx] } else { return false; }; let idx = bitset_chunk_idx[chunk_idx as usize][chunk_piece] as usize; - let word = if let Some(word) = bitset_canonical.get(idx) { - *word + // FIXME: const-hack: Revert to `slice::get` after `const_slice_index` + // feature stabilizes. + let word = if idx < bitset_canonical.len() { + bitset_canonical[idx] } else { let (real_idx, mapping) = bitset_canonicalized[idx - bitset_canonical.len()]; let mut word = bitset_canonical[real_idx as usize]; @@ -94,21 +99,21 @@ fn skip_search<const SOR: usize, const OFFSETS: usize>( offset_idx % 2 == 1 } -pub const UNICODE_VERSION: (u8, u8, u8) = (14, 0, 0); +pub const UNICODE_VERSION: (u8, u8, u8) = (15, 0, 0); #[rustfmt::skip] pub mod alphabetic { - static SHORT_OFFSET_RUNS: [u32; 51] = [ - 706, 33559113, 876615277, 956309270, 1166025910, 1314925568, 1319120901, 1398813696, - 1449151936, 1451271309, 1455465997, 1463867300, 1652619520, 1663105646, 1665203518, - 1711342208, 1797326647, 1891700352, 2044795904, 2397118176, 2485199770, 2495688592, - 2506175535, 2512471040, 2514568775, 2516674560, 2518772281, 2520870464, 2552334328, - 2583792854, 2587996144, 2594287907, 2608968444, 2621553664, 2623656960, 2644629158, - 2722225920, 2770461328, 2808211424, 2816601600, 2850156848, 2988572672, 3001198304, - 3003299641, 3007499938, 3015896033, 3020093440, 3022191134, 3024289792, 3026391883, - 3029603147, + static SHORT_OFFSET_RUNS: [u32; 53] = [ + 706, 33559113, 872420973, 952114966, 1161831606, 1310731264, 1314926597, 1394619392, + 1444957632, 1447077005, 1451271693, 1459672996, 1648425216, 1658911342, 1661009214, + 1707147904, 1793132343, 1887506048, 2040601600, 2392923872, 2481005466, 2504077200, + 2514564144, 2520859648, 2527151687, 2529257472, 2531355193, 2533453376, 2564917240, + 2596375766, 2600579056, 2606870819, 2621551356, 2642525184, 2644628480, 2665600678, + 2743197440, 2791432848, 2841765072, 2850154464, 2854350336, 2887905584, 3026321408, + 3038947040, 3041048378, 3045248674, 3053644769, 3057842176, 3059939870, 3062038528, + 3064140619, 3066241968, 3071550384, ]; - static OFFSETS: [u8; 1445] = [ + static OFFSETS: [u8; 1465] = [ 65, 26, 6, 26, 47, 1, 10, 1, 4, 1, 5, 23, 1, 31, 1, 0, 4, 12, 14, 5, 7, 1, 1, 1, 86, 1, 42, 5, 1, 2, 2, 4, 1, 1, 6, 1, 1, 3, 1, 1, 1, 20, 1, 83, 1, 139, 8, 166, 1, 38, 2, 1, 6, 41, 39, 14, 1, 1, 1, 2, 1, 2, 1, 1, 8, 27, 4, 4, 29, 11, 5, 56, 1, 7, 14, 102, 1, 8, 4, 8, 4, 3, 10, @@ -118,50 +123,51 @@ pub mod alphabetic { 2, 1, 2, 4, 5, 4, 2, 2, 2, 4, 1, 7, 4, 1, 1, 17, 6, 11, 3, 1, 9, 1, 3, 1, 22, 1, 7, 1, 2, 1, 5, 3, 9, 1, 3, 1, 2, 3, 1, 15, 4, 21, 4, 4, 3, 1, 8, 2, 2, 2, 22, 1, 7, 1, 2, 1, 5, 3, 8, 2, 2, 2, 2, 9, 2, 4, 2, 1, 5, 13, 1, 16, 2, 1, 6, 3, 3, 1, 4, 3, 2, 1, 1, 1, 2, 3, 2, 3, 3, 3, - 12, 4, 5, 3, 3, 1, 3, 3, 1, 6, 1, 40, 4, 1, 8, 1, 3, 1, 23, 1, 16, 3, 8, 1, 3, 1, 3, 8, 2, - 1, 3, 2, 1, 2, 4, 28, 4, 1, 8, 1, 3, 1, 23, 1, 10, 1, 5, 3, 8, 1, 3, 1, 3, 8, 2, 6, 2, 1, 4, - 13, 2, 13, 13, 1, 3, 1, 41, 2, 8, 1, 3, 1, 3, 1, 1, 5, 4, 7, 5, 22, 6, 1, 3, 1, 18, 3, 24, - 1, 9, 1, 1, 2, 7, 8, 6, 1, 1, 1, 8, 18, 2, 13, 58, 5, 7, 6, 1, 51, 2, 1, 1, 1, 5, 1, 24, 1, - 1, 1, 19, 1, 3, 2, 5, 1, 1, 6, 1, 14, 4, 32, 1, 63, 8, 1, 36, 4, 17, 6, 16, 1, 36, 67, 55, - 1, 1, 2, 5, 16, 64, 10, 4, 2, 38, 1, 1, 5, 1, 2, 43, 1, 0, 1, 4, 2, 7, 1, 1, 1, 4, 2, 41, 1, - 4, 2, 33, 1, 4, 2, 7, 1, 1, 1, 4, 2, 15, 1, 57, 1, 4, 2, 67, 37, 16, 16, 86, 2, 6, 3, 0, 2, - 17, 1, 26, 5, 75, 3, 11, 7, 20, 11, 21, 12, 20, 12, 13, 1, 3, 1, 2, 12, 52, 2, 19, 14, 1, 4, - 1, 67, 89, 7, 43, 5, 70, 10, 31, 1, 12, 4, 9, 23, 30, 2, 5, 11, 44, 4, 26, 54, 28, 4, 63, 2, - 20, 50, 1, 23, 2, 11, 3, 49, 52, 1, 15, 1, 8, 51, 42, 2, 4, 10, 44, 1, 11, 14, 55, 22, 3, - 10, 36, 2, 9, 7, 43, 2, 3, 41, 4, 1, 6, 1, 2, 3, 1, 5, 192, 39, 14, 11, 0, 2, 6, 2, 38, 2, - 6, 2, 8, 1, 1, 1, 1, 1, 1, 1, 31, 2, 53, 1, 7, 1, 1, 3, 3, 1, 7, 3, 4, 2, 6, 4, 13, 5, 3, 1, - 7, 116, 1, 13, 1, 16, 13, 101, 1, 4, 1, 2, 10, 1, 1, 3, 5, 6, 1, 1, 1, 1, 1, 1, 4, 1, 11, 2, - 4, 5, 5, 4, 1, 17, 41, 0, 52, 0, 229, 6, 4, 3, 2, 12, 38, 1, 1, 5, 1, 2, 56, 7, 1, 16, 23, - 9, 7, 1, 7, 1, 7, 1, 7, 1, 7, 1, 7, 1, 7, 1, 7, 1, 32, 47, 1, 0, 3, 25, 9, 7, 5, 2, 5, 4, - 86, 6, 3, 1, 90, 1, 4, 5, 43, 1, 94, 17, 32, 48, 16, 0, 0, 64, 0, 67, 46, 2, 0, 3, 16, 10, - 2, 20, 47, 5, 8, 3, 113, 39, 9, 2, 103, 2, 64, 5, 2, 1, 1, 1, 5, 24, 20, 1, 33, 24, 52, 12, - 68, 1, 1, 44, 6, 3, 1, 1, 3, 10, 33, 5, 35, 13, 29, 3, 51, 1, 12, 15, 1, 16, 16, 10, 5, 1, - 55, 9, 14, 18, 23, 3, 69, 1, 1, 1, 1, 24, 3, 2, 16, 2, 4, 11, 6, 2, 6, 2, 6, 9, 7, 1, 7, 1, - 43, 1, 14, 6, 123, 21, 0, 12, 23, 4, 49, 0, 0, 2, 106, 38, 7, 12, 5, 5, 12, 1, 13, 1, 5, 1, - 1, 1, 2, 1, 2, 1, 108, 33, 0, 18, 64, 2, 54, 40, 12, 116, 5, 1, 135, 36, 26, 6, 26, 11, 89, - 3, 6, 2, 6, 2, 6, 2, 3, 35, 12, 1, 26, 1, 19, 1, 2, 1, 15, 2, 14, 34, 123, 69, 53, 0, 29, 3, + 12, 4, 5, 3, 3, 1, 3, 3, 1, 6, 1, 40, 13, 1, 3, 1, 23, 1, 16, 3, 8, 1, 3, 1, 3, 8, 2, 1, 3, + 2, 1, 2, 4, 28, 4, 1, 8, 1, 3, 1, 23, 1, 10, 1, 5, 3, 8, 1, 3, 1, 3, 8, 2, 6, 2, 1, 4, 13, + 3, 12, 13, 1, 3, 1, 41, 2, 8, 1, 3, 1, 3, 1, 1, 5, 4, 7, 5, 22, 6, 1, 3, 1, 18, 3, 24, 1, 9, + 1, 1, 2, 7, 8, 6, 1, 1, 1, 8, 18, 2, 13, 58, 5, 7, 6, 1, 51, 2, 1, 1, 1, 5, 1, 24, 1, 1, 1, + 19, 1, 3, 2, 5, 1, 1, 6, 1, 14, 4, 32, 1, 63, 8, 1, 36, 4, 19, 4, 16, 1, 36, 67, 55, 1, 1, + 2, 5, 16, 64, 10, 4, 2, 38, 1, 1, 5, 1, 2, 43, 1, 0, 1, 4, 2, 7, 1, 1, 1, 4, 2, 41, 1, 4, 2, + 33, 1, 4, 2, 7, 1, 1, 1, 4, 2, 15, 1, 57, 1, 4, 2, 67, 37, 16, 16, 86, 2, 6, 3, 0, 2, 17, 1, + 26, 5, 75, 3, 11, 7, 20, 11, 21, 12, 20, 12, 13, 1, 3, 1, 2, 12, 52, 2, 19, 14, 1, 4, 1, 67, + 89, 7, 43, 5, 70, 10, 31, 1, 12, 4, 9, 23, 30, 2, 5, 11, 44, 4, 26, 54, 28, 4, 63, 2, 20, + 50, 1, 23, 2, 11, 3, 49, 52, 1, 15, 1, 8, 51, 42, 2, 4, 10, 44, 1, 11, 14, 55, 22, 3, 10, + 36, 2, 9, 7, 43, 2, 3, 41, 4, 1, 6, 1, 2, 3, 1, 5, 192, 39, 14, 11, 0, 2, 6, 2, 38, 2, 6, 2, + 8, 1, 1, 1, 1, 1, 1, 1, 31, 2, 53, 1, 7, 1, 1, 3, 3, 1, 7, 3, 4, 2, 6, 4, 13, 5, 3, 1, 7, + 116, 1, 13, 1, 16, 13, 101, 1, 4, 1, 2, 10, 1, 1, 3, 5, 6, 1, 1, 1, 1, 1, 1, 4, 1, 11, 2, 4, + 5, 5, 4, 1, 17, 41, 0, 52, 0, 229, 6, 4, 3, 2, 12, 38, 1, 1, 5, 1, 2, 56, 7, 1, 16, 23, 9, + 7, 1, 7, 1, 7, 1, 7, 1, 7, 1, 7, 1, 7, 1, 7, 1, 32, 47, 1, 0, 3, 25, 9, 7, 5, 2, 5, 4, 86, + 6, 3, 1, 90, 1, 4, 5, 43, 1, 94, 17, 32, 48, 16, 0, 0, 64, 0, 67, 46, 2, 0, 3, 16, 10, 2, + 20, 47, 5, 8, 3, 113, 39, 9, 2, 103, 2, 64, 5, 2, 1, 1, 1, 5, 24, 20, 1, 33, 24, 52, 12, 68, + 1, 1, 44, 6, 3, 1, 1, 3, 10, 33, 5, 35, 13, 29, 3, 51, 1, 12, 15, 1, 16, 16, 10, 5, 1, 55, + 9, 14, 18, 23, 3, 69, 1, 1, 1, 1, 24, 3, 2, 16, 2, 4, 11, 6, 2, 6, 2, 6, 9, 7, 1, 7, 1, 43, + 1, 14, 6, 123, 21, 0, 12, 23, 4, 49, 0, 0, 2, 106, 38, 7, 12, 5, 5, 12, 1, 13, 1, 5, 1, 1, + 1, 2, 1, 2, 1, 108, 33, 0, 18, 64, 2, 54, 40, 12, 116, 5, 1, 135, 36, 26, 6, 26, 11, 89, 3, + 6, 2, 6, 2, 6, 2, 3, 35, 12, 1, 26, 1, 19, 1, 2, 1, 15, 2, 14, 34, 123, 69, 53, 0, 29, 3, 49, 47, 32, 13, 30, 5, 43, 5, 30, 2, 36, 4, 8, 1, 5, 42, 158, 18, 36, 4, 36, 4, 40, 8, 52, 12, 11, 1, 15, 1, 7, 1, 2, 1, 11, 1, 15, 1, 7, 1, 2, 67, 0, 9, 22, 10, 8, 24, 6, 1, 42, 1, 9, 69, 6, 2, 1, 1, 44, 1, 2, 3, 1, 2, 23, 10, 23, 9, 31, 65, 19, 1, 2, 10, 22, 10, 26, 70, 56, 6, 2, 64, 4, 1, 2, 5, 8, 1, 3, 1, 29, 42, 29, 3, 29, 35, 8, 1, 28, 27, 54, 10, 22, 10, 19, 13, 18, 110, 73, 55, 51, 13, 51, 13, 40, 0, 42, 1, 2, 3, 2, 78, 29, 10, 1, 8, 22, 42, - 18, 46, 21, 27, 23, 9, 70, 43, 5, 12, 55, 9, 1, 13, 25, 23, 51, 17, 4, 8, 35, 3, 1, 9, 64, - 1, 4, 9, 2, 10, 1, 1, 1, 35, 18, 1, 34, 2, 1, 6, 1, 65, 7, 1, 1, 1, 4, 1, 15, 1, 10, 7, 57, + 18, 46, 21, 27, 23, 9, 70, 43, 5, 10, 57, 9, 1, 13, 25, 23, 51, 17, 4, 8, 35, 3, 1, 9, 64, + 1, 4, 9, 2, 10, 1, 1, 1, 35, 18, 1, 34, 2, 1, 6, 4, 62, 7, 1, 1, 1, 4, 1, 15, 1, 10, 7, 57, 23, 4, 1, 8, 2, 2, 2, 22, 1, 7, 1, 2, 1, 5, 3, 8, 2, 2, 2, 2, 3, 1, 6, 1, 5, 7, 156, 66, 1, 3, 1, 4, 20, 3, 30, 66, 2, 2, 1, 1, 184, 54, 2, 7, 25, 6, 34, 63, 1, 1, 3, 1, 59, 54, 2, 1, 71, 27, 2, 14, 21, 7, 185, 57, 103, 64, 31, 8, 2, 1, 2, 8, 1, 2, 1, 30, 1, 2, 2, 2, 2, 4, 93, 8, 2, 46, 2, 6, 1, 1, 1, 2, 27, 51, 2, 10, 17, 72, 5, 1, 18, 73, 0, 9, 1, 45, 1, 7, 1, 1, 49, 30, 2, 22, 1, 14, 73, 7, 1, 2, 1, 44, 3, 1, 1, 2, 1, 3, 1, 1, 2, 2, 24, 6, 1, 2, 1, - 37, 1, 2, 1, 4, 1, 1, 0, 23, 185, 1, 79, 0, 102, 111, 17, 196, 0, 97, 15, 0, 0, 0, 0, 0, 7, - 31, 17, 79, 17, 30, 18, 48, 16, 4, 31, 21, 5, 19, 0, 64, 128, 75, 4, 57, 7, 17, 64, 2, 1, 1, - 12, 2, 14, 0, 8, 0, 42, 9, 0, 4, 1, 7, 1, 2, 1, 0, 45, 3, 17, 4, 8, 0, 0, 107, 5, 13, 3, 9, - 7, 10, 4, 1, 0, 85, 1, 71, 1, 2, 2, 1, 2, 2, 2, 4, 1, 12, 1, 1, 1, 7, 1, 65, 1, 4, 2, 8, 1, - 7, 1, 28, 1, 4, 1, 5, 1, 1, 3, 7, 1, 0, 2, 25, 1, 25, 1, 31, 1, 25, 1, 31, 1, 25, 1, 31, 1, - 25, 1, 31, 1, 25, 1, 8, 0, 31, 225, 7, 1, 17, 2, 7, 1, 2, 1, 5, 213, 45, 10, 7, 16, 1, 0, - 30, 18, 44, 0, 7, 1, 4, 1, 2, 1, 15, 1, 197, 59, 68, 3, 1, 3, 1, 0, 4, 1, 27, 1, 2, 1, 1, 2, - 1, 1, 10, 1, 4, 1, 1, 1, 1, 6, 1, 4, 1, 1, 1, 1, 1, 1, 3, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, - 1, 1, 1, 1, 2, 1, 1, 2, 4, 1, 7, 1, 4, 1, 4, 1, 1, 1, 10, 1, 17, 5, 3, 1, 5, 1, 17, 0, 26, - 6, 26, 6, 26, 0, 0, 32, 0, 7, 222, 2, 0, 14, 0, 0, 0, 0, 0, 0, + 37, 1, 2, 1, 4, 1, 1, 0, 23, 9, 17, 1, 41, 3, 3, 111, 1, 79, 0, 102, 111, 17, 196, 0, 97, + 15, 0, 17, 6, 0, 0, 0, 0, 7, 31, 17, 79, 17, 30, 18, 48, 16, 4, 31, 21, 5, 19, 0, 64, 128, + 75, 4, 57, 7, 17, 64, 2, 1, 1, 12, 2, 14, 0, 8, 0, 42, 9, 0, 4, 1, 7, 1, 2, 1, 0, 15, 1, 29, + 3, 2, 1, 14, 4, 8, 0, 0, 107, 5, 13, 3, 9, 7, 10, 4, 1, 0, 85, 1, 71, 1, 2, 2, 1, 2, 2, 2, + 4, 1, 12, 1, 1, 1, 7, 1, 65, 1, 4, 2, 8, 1, 7, 1, 28, 1, 4, 1, 5, 1, 1, 3, 7, 1, 0, 2, 25, + 1, 25, 1, 31, 1, 25, 1, 31, 1, 25, 1, 31, 1, 25, 1, 31, 1, 25, 1, 8, 0, 31, 6, 6, 213, 7, 1, + 17, 2, 7, 1, 2, 1, 5, 5, 62, 33, 1, 112, 45, 10, 7, 16, 1, 0, 30, 18, 44, 0, 28, 0, 7, 1, 4, + 1, 2, 1, 15, 1, 197, 59, 68, 3, 1, 3, 1, 0, 4, 1, 27, 1, 2, 1, 1, 2, 1, 1, 10, 1, 4, 1, 1, + 1, 1, 6, 1, 4, 1, 1, 1, 1, 1, 1, 3, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, + 4, 1, 7, 1, 4, 1, 4, 1, 1, 1, 10, 1, 17, 5, 3, 1, 5, 1, 17, 0, 26, 6, 26, 6, 26, 0, 0, 32, + 0, 6, 222, 2, 0, 14, 0, 0, 0, 0, 0, 5, 0, 0, ]; pub fn lookup(c: char) -> bool { super::skip_search( @@ -177,11 +183,11 @@ pub mod case_ignorable { static SHORT_OFFSET_RUNS: [u32; 35] = [ 688, 44045149, 572528402, 576724925, 807414908, 878718981, 903913493, 929080568, 933275148, 937491230, 1138818560, 1147208189, 1210124160, 1222707713, 1235291428, 1260457643, - 1264654383, 1491147067, 1499536432, 1558257395, 1621177392, 1625385712, 1629581135, - 1642180592, 1658961053, 1671548672, 1679937895, 1688328704, 1709301760, 1734467888, - 1755439790, 1759635664, 1768027131, 1777205249, 1782514160, + 1264654383, 1499535675, 1507925040, 1566646003, 1629566000, 1650551536, 1658941263, + 1671540720, 1688321181, 1700908800, 1709298023, 1717688832, 1738661888, 1763828398, + 1797383403, 1805773008, 1809970171, 1819148289, 1824457200, ]; - static OFFSETS: [u8; 855] = [ + static OFFSETS: [u8; 875] = [ 39, 1, 6, 1, 11, 1, 35, 1, 1, 1, 71, 1, 4, 1, 1, 1, 4, 1, 2, 2, 0, 192, 4, 2, 4, 1, 9, 2, 1, 1, 251, 7, 207, 1, 5, 1, 49, 45, 1, 1, 1, 2, 1, 2, 1, 1, 44, 1, 11, 6, 10, 11, 1, 1, 35, 1, 10, 21, 16, 1, 101, 8, 1, 10, 1, 4, 33, 1, 1, 1, 30, 27, 91, 11, 58, 11, 4, 1, 2, 1, 24, @@ -190,7 +196,7 @@ pub mod case_ignorable { 57, 1, 4, 5, 1, 2, 4, 1, 20, 2, 22, 6, 1, 1, 58, 1, 2, 1, 1, 4, 8, 1, 7, 2, 11, 2, 30, 1, 61, 1, 12, 1, 50, 1, 3, 1, 55, 1, 1, 3, 5, 3, 1, 4, 7, 2, 11, 2, 29, 1, 58, 1, 2, 1, 6, 1, 5, 2, 20, 2, 28, 2, 57, 2, 4, 4, 8, 1, 20, 2, 29, 1, 72, 1, 7, 3, 1, 1, 90, 1, 2, 7, 11, 9, - 98, 1, 2, 9, 9, 1, 1, 6, 74, 2, 27, 1, 1, 1, 1, 1, 55, 14, 1, 5, 1, 2, 5, 11, 1, 36, 9, 1, + 98, 1, 2, 9, 9, 1, 1, 7, 73, 2, 27, 1, 1, 1, 1, 1, 55, 14, 1, 5, 1, 2, 5, 11, 1, 36, 9, 1, 102, 4, 1, 6, 1, 2, 2, 2, 25, 2, 4, 3, 16, 4, 13, 1, 2, 2, 6, 1, 15, 1, 94, 1, 0, 3, 0, 3, 29, 2, 30, 2, 30, 2, 64, 2, 1, 7, 8, 1, 2, 11, 3, 1, 5, 1, 45, 5, 51, 1, 65, 2, 34, 1, 118, 3, 4, 2, 9, 1, 6, 3, 219, 2, 2, 1, 58, 1, 1, 7, 1, 1, 1, 1, 2, 8, 6, 10, 2, 1, 39, 1, 8, 31, @@ -204,15 +210,16 @@ pub mod case_ignorable { 1, 1, 27, 1, 14, 2, 5, 2, 1, 1, 100, 5, 9, 3, 121, 1, 2, 1, 4, 1, 0, 1, 147, 17, 0, 16, 3, 1, 12, 16, 34, 1, 2, 1, 169, 1, 7, 1, 6, 1, 11, 1, 35, 1, 1, 1, 47, 1, 45, 2, 67, 1, 21, 3, 0, 1, 226, 1, 149, 5, 0, 6, 1, 42, 1, 9, 0, 3, 1, 2, 5, 4, 40, 3, 4, 1, 165, 2, 0, 4, 0, 2, - 153, 11, 49, 4, 123, 1, 54, 15, 41, 1, 2, 2, 10, 3, 49, 4, 2, 2, 2, 1, 4, 1, 10, 1, 50, 3, - 36, 5, 1, 8, 62, 1, 12, 2, 52, 9, 10, 4, 2, 1, 95, 3, 2, 1, 1, 2, 6, 1, 160, 1, 3, 8, 21, 2, - 57, 2, 3, 1, 37, 7, 3, 5, 195, 8, 2, 3, 1, 1, 23, 1, 84, 6, 1, 1, 4, 2, 1, 2, 238, 4, 6, 2, - 1, 2, 27, 2, 85, 8, 2, 1, 1, 2, 106, 1, 1, 1, 2, 6, 1, 1, 101, 3, 2, 4, 1, 5, 0, 9, 1, 2, 0, - 2, 1, 1, 4, 1, 144, 4, 2, 2, 4, 1, 32, 10, 40, 6, 2, 4, 8, 1, 9, 6, 2, 3, 46, 13, 1, 2, 0, - 7, 1, 6, 1, 1, 82, 22, 2, 7, 1, 2, 1, 2, 122, 6, 3, 1, 1, 2, 1, 7, 1, 1, 72, 2, 3, 1, 1, 1, - 0, 2, 0, 9, 0, 5, 59, 7, 9, 4, 0, 1, 63, 17, 64, 2, 1, 2, 0, 4, 1, 7, 1, 2, 0, 2, 1, 4, 0, - 46, 2, 23, 0, 3, 9, 16, 2, 7, 30, 4, 148, 3, 0, 55, 4, 50, 8, 1, 14, 1, 22, 5, 1, 15, 0, 7, - 1, 17, 2, 7, 1, 2, 1, 5, 0, 14, 0, 1, 61, 4, 0, 7, 109, 8, 0, 5, 0, 1, 30, 96, 128, 240, 0, + 80, 3, 70, 11, 49, 4, 123, 1, 54, 15, 41, 1, 2, 2, 10, 3, 49, 4, 2, 2, 2, 1, 4, 1, 10, 1, + 50, 3, 36, 5, 1, 8, 62, 1, 12, 2, 52, 9, 10, 4, 2, 1, 95, 3, 2, 1, 1, 2, 6, 1, 2, 1, 157, 1, + 3, 8, 21, 2, 57, 2, 3, 1, 37, 7, 3, 5, 195, 8, 2, 3, 1, 1, 23, 1, 84, 6, 1, 1, 4, 2, 1, 2, + 238, 4, 6, 2, 1, 2, 27, 2, 85, 8, 2, 1, 1, 2, 106, 1, 1, 1, 2, 6, 1, 1, 101, 3, 2, 4, 1, 5, + 0, 9, 1, 2, 0, 2, 1, 1, 4, 1, 144, 4, 2, 2, 4, 1, 32, 10, 40, 6, 2, 4, 8, 1, 9, 6, 2, 3, 46, + 13, 1, 2, 0, 7, 1, 6, 1, 1, 82, 22, 2, 7, 1, 2, 1, 2, 122, 6, 3, 1, 1, 2, 1, 7, 1, 1, 72, 2, + 3, 1, 1, 1, 0, 2, 11, 2, 52, 5, 5, 1, 1, 1, 0, 17, 6, 15, 0, 5, 59, 7, 9, 4, 0, 1, 63, 17, + 64, 2, 1, 2, 0, 4, 1, 7, 1, 2, 0, 2, 1, 4, 0, 46, 2, 23, 0, 3, 9, 16, 2, 7, 30, 4, 148, 3, + 0, 55, 4, 50, 8, 1, 14, 1, 22, 5, 1, 15, 0, 7, 1, 17, 2, 7, 1, 2, 1, 5, 5, 62, 33, 1, 160, + 14, 0, 1, 61, 4, 0, 5, 0, 7, 109, 8, 0, 5, 0, 1, 30, 96, 128, 240, 0, ]; pub fn lookup(c: char) -> bool { super::skip_search( @@ -225,24 +232,24 @@ pub mod case_ignorable { #[rustfmt::skip] pub mod cased { - static SHORT_OFFSET_RUNS: [u32; 21] = [ + static SHORT_OFFSET_RUNS: [u32; 22] = [ 4256, 115348384, 136322176, 144711446, 163587254, 320875520, 325101120, 350268208, 392231680, 404815649, 413205504, 421595008, 467733632, 484513952, 492924480, 497144832, - 501339814, 578936576, 627173632, 635564336, 640872842, + 501339814, 578936576, 627171376, 639756544, 643952944, 649261450, ]; - static OFFSETS: [u8; 311] = [ + static OFFSETS: [u8; 315] = [ 65, 26, 6, 26, 47, 1, 10, 1, 4, 1, 5, 23, 1, 31, 1, 195, 1, 4, 4, 208, 1, 36, 7, 2, 30, 5, 96, 1, 42, 4, 2, 2, 2, 4, 1, 1, 6, 1, 1, 3, 1, 1, 1, 20, 1, 83, 1, 139, 8, 166, 1, 38, 9, - 41, 0, 38, 1, 1, 5, 1, 2, 43, 2, 3, 0, 86, 2, 6, 0, 9, 7, 43, 2, 3, 64, 192, 64, 0, 2, 6, 2, + 41, 0, 38, 1, 1, 5, 1, 2, 43, 1, 4, 0, 86, 2, 6, 0, 9, 7, 43, 2, 3, 64, 192, 64, 0, 2, 6, 2, 38, 2, 6, 2, 8, 1, 1, 1, 1, 1, 1, 1, 31, 2, 53, 1, 7, 1, 1, 3, 3, 1, 7, 3, 4, 2, 6, 4, 13, 5, 3, 1, 7, 116, 1, 13, 1, 16, 13, 101, 1, 4, 1, 2, 10, 1, 1, 3, 5, 6, 1, 1, 1, 1, 1, 1, 4, 1, 6, 4, 1, 2, 4, 5, 5, 4, 1, 17, 32, 3, 2, 0, 52, 0, 229, 6, 4, 3, 2, 12, 38, 1, 1, 5, 1, - 0, 46, 18, 30, 132, 102, 3, 4, 1, 59, 5, 2, 1, 1, 1, 5, 27, 2, 1, 3, 0, 43, 1, 13, 7, 80, 0, + 0, 46, 18, 30, 132, 102, 3, 4, 1, 59, 5, 2, 1, 1, 1, 5, 24, 5, 1, 3, 0, 43, 1, 14, 6, 80, 0, 7, 12, 5, 0, 26, 6, 26, 0, 80, 96, 36, 4, 36, 116, 11, 1, 15, 1, 7, 1, 2, 1, 11, 1, 15, 1, 7, 1, 2, 0, 1, 2, 3, 1, 42, 1, 9, 0, 51, 13, 51, 0, 64, 0, 64, 0, 85, 1, 71, 1, 2, 2, 1, 2, 2, 2, 4, 1, 12, 1, 1, 1, 7, 1, 65, 1, 4, 2, 8, 1, 7, 1, 28, 1, 4, 1, 5, 1, 1, 3, 7, 1, 0, 2, - 25, 1, 25, 1, 31, 1, 25, 1, 31, 1, 25, 1, 31, 1, 25, 1, 31, 1, 25, 1, 8, 0, 10, 1, 20, 0, - 68, 0, 26, 6, 26, 6, 26, 0, + 25, 1, 25, 1, 31, 1, 25, 1, 31, 1, 25, 1, 31, 1, 25, 1, 31, 1, 25, 1, 8, 0, 10, 1, 20, 6, 6, + 0, 62, 0, 68, 0, 26, 6, 26, 6, 26, 0, ]; pub fn lookup(c: char) -> bool { super::skip_search( @@ -272,14 +279,14 @@ pub mod cc { #[rustfmt::skip] pub mod grapheme_extend { - static SHORT_OFFSET_RUNS: [u32; 32] = [ + static SHORT_OFFSET_RUNS: [u32; 33] = [ 768, 2098307, 6292881, 10490717, 522196754, 526393356, 731917551, 740306986, 752920175, 761309186, 778107678, 908131840, 912326558, 920715773, 924912129, 937495844, 962662059, - 966858799, 1205935152, 1277239027, 1340173040, 1344368463, 1352776861, 1365364480, - 1369559397, 1377950208, 1407311872, 1432478000, 1453449902, 1457645776, 1466826784, - 1476329968, + 966858799, 1214323760, 1285627635, 1348547648, 1369533168, 1377922895, 1386331293, + 1398918912, 1403113829, 1411504640, 1440866304, 1466032814, 1495393516, 1503783120, + 1508769824, 1518273008, ]; - static OFFSETS: [u8; 707] = [ + static OFFSETS: [u8; 727] = [ 0, 112, 0, 7, 0, 45, 1, 1, 1, 2, 1, 2, 1, 1, 72, 11, 48, 21, 16, 1, 101, 7, 2, 6, 2, 2, 1, 4, 35, 1, 30, 27, 91, 11, 58, 9, 9, 1, 24, 4, 1, 9, 1, 3, 1, 5, 43, 3, 60, 8, 42, 24, 1, 32, 55, 1, 1, 1, 4, 8, 4, 1, 3, 7, 10, 2, 29, 1, 58, 1, 1, 1, 2, 4, 8, 1, 9, 1, 10, 2, 26, 1, 2, @@ -287,7 +294,7 @@ pub mod grapheme_extend { 1, 1, 58, 1, 1, 2, 1, 4, 8, 1, 7, 3, 10, 2, 30, 1, 59, 1, 1, 1, 12, 1, 9, 1, 40, 1, 3, 1, 55, 1, 1, 3, 5, 3, 1, 4, 7, 2, 11, 2, 29, 1, 58, 1, 2, 1, 2, 1, 3, 1, 5, 2, 7, 2, 11, 2, 28, 2, 57, 2, 1, 1, 2, 4, 8, 1, 9, 1, 10, 2, 29, 1, 72, 1, 4, 1, 2, 3, 1, 1, 8, 1, 81, 1, 2, 7, - 12, 8, 98, 1, 2, 9, 11, 6, 74, 2, 27, 1, 1, 1, 1, 1, 55, 14, 1, 5, 1, 2, 5, 11, 1, 36, 9, 1, + 12, 8, 98, 1, 2, 9, 11, 7, 73, 2, 27, 1, 1, 1, 1, 1, 55, 14, 1, 5, 1, 2, 5, 11, 1, 36, 9, 1, 102, 4, 1, 6, 1, 2, 2, 2, 25, 2, 4, 3, 16, 4, 13, 1, 2, 2, 6, 1, 15, 1, 0, 3, 0, 3, 29, 2, 30, 2, 30, 2, 64, 2, 1, 7, 8, 1, 2, 11, 9, 1, 45, 3, 1, 1, 117, 2, 34, 1, 118, 3, 4, 2, 9, 1, 6, 3, 219, 2, 2, 1, 58, 1, 1, 7, 1, 1, 1, 1, 2, 8, 6, 10, 2, 1, 48, 31, 49, 4, 48, 7, 1, @@ -296,16 +303,17 @@ pub mod grapheme_extend { 4, 1, 10, 32, 2, 80, 2, 0, 1, 3, 1, 4, 1, 25, 2, 5, 1, 151, 2, 26, 18, 13, 1, 38, 8, 25, 11, 46, 3, 48, 1, 2, 4, 2, 2, 39, 1, 67, 6, 2, 2, 2, 2, 12, 1, 8, 1, 47, 1, 51, 1, 1, 3, 2, 2, 5, 2, 1, 1, 42, 2, 8, 1, 238, 1, 2, 1, 4, 1, 0, 1, 0, 16, 16, 16, 0, 2, 0, 1, 226, 1, 149, - 5, 0, 3, 1, 2, 5, 4, 40, 3, 4, 1, 165, 2, 0, 4, 0, 2, 153, 11, 49, 4, 123, 1, 54, 15, 41, 1, - 2, 2, 10, 3, 49, 4, 2, 2, 7, 1, 61, 3, 36, 5, 1, 8, 62, 1, 12, 2, 52, 9, 10, 4, 2, 1, 95, 3, - 2, 1, 1, 2, 6, 1, 160, 1, 3, 8, 21, 2, 57, 2, 1, 1, 1, 1, 22, 1, 14, 7, 3, 5, 195, 8, 2, 3, - 1, 1, 23, 1, 81, 1, 2, 6, 1, 1, 2, 1, 1, 2, 1, 2, 235, 1, 2, 4, 6, 2, 1, 2, 27, 2, 85, 8, 2, - 1, 1, 2, 106, 1, 1, 1, 2, 6, 1, 1, 101, 3, 2, 4, 1, 5, 0, 9, 1, 2, 245, 1, 10, 2, 1, 1, 4, - 1, 144, 4, 2, 2, 4, 1, 32, 10, 40, 6, 2, 4, 8, 1, 9, 6, 2, 3, 46, 13, 1, 2, 0, 7, 1, 6, 1, - 1, 82, 22, 2, 7, 1, 2, 1, 2, 122, 6, 3, 1, 1, 2, 1, 7, 1, 1, 72, 2, 3, 1, 1, 1, 0, 2, 0, 5, - 59, 7, 0, 1, 63, 4, 81, 1, 0, 2, 0, 46, 2, 23, 0, 1, 1, 3, 4, 5, 8, 8, 2, 7, 30, 4, 148, 3, - 0, 55, 4, 50, 8, 1, 14, 1, 22, 5, 1, 15, 0, 7, 1, 17, 2, 7, 1, 2, 1, 5, 0, 7, 0, 1, 61, 4, - 0, 7, 109, 7, 0, 96, 128, 240, 0, + 5, 0, 3, 1, 2, 5, 4, 40, 3, 4, 1, 165, 2, 0, 4, 0, 2, 80, 3, 70, 11, 49, 4, 123, 1, 54, 15, + 41, 1, 2, 2, 10, 3, 49, 4, 2, 2, 7, 1, 61, 3, 36, 5, 1, 8, 62, 1, 12, 2, 52, 9, 10, 4, 2, 1, + 95, 3, 2, 1, 1, 2, 6, 1, 2, 1, 157, 1, 3, 8, 21, 2, 57, 2, 1, 1, 1, 1, 22, 1, 14, 7, 3, 5, + 195, 8, 2, 3, 1, 1, 23, 1, 81, 1, 2, 6, 1, 1, 2, 1, 1, 2, 1, 2, 235, 1, 2, 4, 6, 2, 1, 2, + 27, 2, 85, 8, 2, 1, 1, 2, 106, 1, 1, 1, 2, 6, 1, 1, 101, 3, 2, 4, 1, 5, 0, 9, 1, 2, 245, 1, + 10, 2, 1, 1, 4, 1, 144, 4, 2, 2, 4, 1, 32, 10, 40, 6, 2, 4, 8, 1, 9, 6, 2, 3, 46, 13, 1, 2, + 0, 7, 1, 6, 1, 1, 82, 22, 2, 7, 1, 2, 1, 2, 122, 6, 3, 1, 1, 2, 1, 7, 1, 1, 72, 2, 3, 1, 1, + 1, 0, 2, 11, 2, 52, 5, 5, 1, 1, 1, 0, 1, 6, 15, 0, 5, 59, 7, 0, 1, 63, 4, 81, 1, 0, 2, 0, + 46, 2, 23, 0, 1, 1, 3, 4, 5, 8, 8, 2, 7, 30, 4, 148, 3, 0, 55, 4, 50, 8, 1, 14, 1, 22, 5, 1, + 15, 0, 7, 1, 17, 2, 7, 1, 2, 1, 5, 100, 1, 160, 7, 0, 1, 61, 4, 0, 4, 0, 7, 109, 7, 0, 96, + 128, 240, 0, ]; pub fn lookup(c: char) -> bool { super::skip_search( @@ -318,54 +326,56 @@ pub mod grapheme_extend { #[rustfmt::skip] pub mod lowercase { - static BITSET_CHUNKS_MAP: [u8; 123] = [ + const BITSET_CHUNKS_MAP: &'static [u8; 123] = &[ 14, 17, 0, 0, 9, 0, 0, 12, 13, 10, 0, 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 1, 0, 15, 0, 8, 0, 0, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 18, 0, - 3, 0, 0, 7, + 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 19, 0, + 3, 18, 0, 7, ]; - static BITSET_INDEX_CHUNKS: [[u8; 16]; 19] = [ + const BITSET_INDEX_CHUNKS: &'static [[u8; 16]; 20] = &[ [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 59, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 14, 55, 0], - [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 41, 0, 0, 0], - [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 43, 0, 0, 0], + [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 40, 0, 0, 0], + [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 44, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 0, 0], - [0, 0, 0, 0, 0, 0, 0, 0, 0, 65, 42, 0, 50, 46, 48, 32], + [0, 0, 0, 0, 0, 0, 0, 0, 0, 65, 43, 0, 51, 47, 49, 33], [0, 0, 0, 0, 10, 56, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], - [0, 0, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], - [0, 0, 0, 53, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 26], + [0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + [0, 0, 0, 19, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 27], [0, 0, 0, 60, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], - [0, 0, 0, 70, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], - [0, 0, 57, 0, 55, 55, 55, 0, 21, 21, 67, 21, 35, 24, 23, 36], - [0, 5, 74, 0, 28, 15, 72, 0, 0, 0, 0, 0, 0, 0, 0, 0], - [0, 64, 33, 17, 22, 51, 52, 47, 45, 8, 34, 40, 0, 27, 13, 30], - [11, 58, 0, 4, 0, 0, 29, 0, 0, 0, 0, 0, 0, 0, 31, 0], - [16, 25, 21, 37, 38, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], - [16, 49, 2, 20, 66, 9, 57, 0, 0, 0, 0, 0, 0, 0, 0, 0], - [63, 39, 54, 12, 73, 61, 18, 1, 6, 62, 71, 19, 68, 69, 3, 44], + [0, 0, 0, 69, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + [0, 0, 57, 0, 55, 55, 55, 0, 22, 22, 67, 22, 36, 25, 24, 37], + [0, 5, 68, 0, 29, 15, 73, 0, 0, 0, 0, 0, 0, 0, 0, 0], + [0, 64, 34, 17, 23, 52, 53, 48, 46, 8, 35, 42, 0, 28, 13, 31], + [11, 58, 0, 6, 0, 0, 30, 0, 0, 0, 0, 0, 0, 0, 32, 0], + [16, 26, 22, 38, 39, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + [16, 50, 2, 21, 66, 9, 57, 0, 0, 0, 0, 0, 0, 0, 0, 0], + [16, 70, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], + [63, 41, 54, 12, 75, 61, 18, 1, 7, 62, 74, 20, 71, 72, 4, 45], ]; - static BITSET_CANONICAL: [u64; 55] = [ + const BITSET_CANONICAL: &'static [u64; 55] = &[ 0b0000000000000000000000000000000000000000000000000000000000000000, 0b1111111111111111110000000000000000000000000011111111111111111111, 0b1010101010101010101010101010101010101010101010101010100000000010, + 0b0000000000000111111111111111111111111111111111111111111111111111, 0b1111111111111111111111000000000000000000000000001111110111111111, - 0b0000111111111111111111111111111111111111000000000000000000000000, 0b1000000000000010000000000000000000000000000000000000000000000000, + 0b0000111111111111111111111111111111111111000000000000000000000000, 0b0000111111111111111111111111110000000000000000000000000011111111, - 0b0000000000000111111111111111111111111111111111111111111111111111, 0b1111111111111111111111111111111111111111111111111010101010000101, 0b1111111111111111111111111111111100000000000000000000000000000000, 0b1111111111111111111111111111110000000000000000000000000000000000, 0b1111111111111111111111110000000000000000000000000000000000000000, 0b1111111111111111111111000000000000000000000000001111111111101111, 0b1111111111111111111100000000000000000000000000010000000000000000, - 0b1111111111111111000000011111111111110111111111111111111111111111, + 0b1111111111111111000000111111111111110111111111111111111111111111, 0b1111111111111111000000000000000000000000000000000100001111000000, 0b1111111111111111000000000000000000000000000000000000000000000000, 0b1111111101111111111111111111111110000000000000000000000000000000, 0b1111110000000000000000000000000011111111111111111111111111000000, + 0b1111011111111111111111111111111111111111111111110000000000000000, 0b1111000000000000000000000000001111110111111111111111111111111100, 0b1010101010101010101010101010101010101010101010101101010101010100, 0b1010101010101010101010101010101010101010101010101010101010101010, @@ -379,16 +389,16 @@ pub mod lowercase { 0b0001101111111011111111111111101111111111100000000000000000000000, 0b0001100100101111101010101010101010101010111000110111111111111111, 0b0000011111111101111111111111111111111111111111111111111110111001, - 0b0000011101000000000000000000000000000010101010100000010100001010, + 0b0000011101011100000000000000000000000010101010100000010100001010, 0b0000010000100000000001000000000000000000000000000000000000000000, 0b0000000111111111111111111111111111111111111011111111111111111111, 0b0000000011111111000000001111111100000000001111110000000011111111, 0b0000000011011100000000001111111100000000110011110000000011011100, 0b0000000000001000010100000001101010101010101010101010101010101010, 0b0000000000000000001000001011111111111111111111111111111111111111, + 0b0000000000000000000001111110000001111111111111111111101111111111, 0b0000000000000000000000001111111111111111110111111100000000000000, 0b0000000000000000000000000001111100000000000000000000000000000011, - 0b0000000000000000000000000000000001111111111111111111101111111111, 0b0000000000000000000000000000000000111010101010101010101010101010, 0b0000000000000000000000000000000000000000111110000000000001111111, 0b0000000000000000000000000000000000000000000000000000101111110111, @@ -400,16 +410,16 @@ pub mod lowercase { 0b1010101010101011101010101010100000000000000000000000000000000000, 0b1101010010101010101010101010101010101010101010101010101101010101, 0b1110011001010001001011010010101001001110001001000011000100101001, - 0b1110011111111111111111111111111111111111111111110000000000000000, 0b1110101111000000000000000000000000001111111111111111111111111100, ]; - static BITSET_MAPPING: [(u8, u8); 20] = [ + const BITSET_MAPPING: &'static [(u8, u8); 21] = &[ (0, 64), (1, 188), (1, 183), (1, 176), (1, 109), (1, 124), (1, 126), (1, 66), (1, 70), - (1, 77), (2, 146), (2, 144), (2, 83), (3, 12), (3, 6), (4, 156), (4, 78), (5, 187), - (6, 132), (7, 93), + (1, 77), (2, 146), (2, 144), (2, 83), (3, 93), (3, 147), (3, 133), (4, 12), (4, 6), + (5, 187), (6, 78), (7, 132), ]; - pub fn lookup(c: char) -> bool { + #[rustc_const_unstable(feature = "const_unicode_case_lookup", issue = "101400")] + pub const fn lookup(c: char) -> bool { super::bitset_search( c as u32, &BITSET_CHUNKS_MAP, @@ -422,14 +432,14 @@ pub mod lowercase { #[rustfmt::skip] pub mod n { - static SHORT_OFFSET_RUNS: [u32; 38] = [ + static SHORT_OFFSET_RUNS: [u32; 39] = [ 1632, 18876774, 31461440, 102765417, 111154926, 115349830, 132128880, 165684320, 186656630, 195046653, 199241735, 203436434, 216049184, 241215536, 249605104, 274792208, 278987015, 283181793, 295766104, 320933114, 383848032, 392238160, 434181712, 442570976, 455154768, - 463544256, 476128256, 480340576, 484535936, 501338848, 505534414, 513925440, 518120176, - 522315975, 526511217, 534900992, 555875312, 561183738, + 463544144, 476128256, 484534880, 488730240, 505533120, 509728718, 522314048, 526508784, + 530703600, 534898887, 539094129, 547483904, 568458224, 573766650, ]; - static OFFSETS: [u8; 269] = [ + static OFFSETS: [u8; 275] = [ 48, 10, 120, 2, 5, 1, 2, 3, 0, 10, 134, 10, 198, 10, 0, 10, 118, 10, 4, 6, 108, 10, 118, 10, 118, 10, 2, 6, 110, 13, 115, 10, 8, 7, 103, 10, 104, 7, 7, 19, 109, 10, 96, 10, 118, 10, 70, 20, 0, 10, 70, 10, 0, 20, 0, 3, 239, 10, 6, 10, 22, 10, 0, 10, 128, 11, 165, 10, 6, 10, @@ -439,9 +449,9 @@ pub mod n { 29, 1, 8, 1, 134, 5, 202, 10, 0, 8, 25, 7, 39, 9, 75, 5, 22, 6, 160, 2, 2, 16, 2, 46, 64, 9, 52, 2, 30, 3, 75, 5, 104, 8, 24, 8, 41, 7, 0, 6, 48, 10, 0, 31, 158, 10, 42, 4, 112, 7, 134, 30, 128, 10, 60, 10, 144, 10, 7, 20, 251, 10, 0, 10, 118, 10, 0, 10, 102, 10, 102, 12, 0, - 19, 93, 10, 0, 29, 227, 10, 70, 10, 0, 21, 0, 111, 0, 10, 86, 10, 134, 10, 1, 7, 0, 23, 0, - 20, 108, 25, 0, 50, 0, 10, 0, 10, 0, 9, 128, 10, 0, 59, 1, 3, 1, 4, 76, 45, 1, 15, 0, 13, 0, - 10, 0, + 19, 93, 10, 0, 29, 227, 10, 70, 10, 0, 10, 102, 21, 0, 111, 0, 10, 86, 10, 134, 10, 1, 7, 0, + 23, 0, 20, 12, 20, 108, 25, 0, 50, 0, 10, 0, 10, 0, 10, 0, 9, 128, 10, 0, 59, 1, 3, 1, 4, + 76, 45, 1, 15, 0, 13, 0, 10, 0, ]; pub fn lookup(c: char) -> bool { super::skip_search( @@ -454,14 +464,14 @@ pub mod n { #[rustfmt::skip] pub mod uppercase { - static BITSET_CHUNKS_MAP: [u8; 125] = [ + const BITSET_CHUNKS_MAP: &'static [u8; 125] = &[ 12, 15, 6, 6, 0, 6, 6, 2, 4, 11, 6, 16, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 5, 6, 14, 6, 10, 6, 6, 1, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 13, 6, 6, 6, 6, 9, 6, 3, ]; - static BITSET_INDEX_CHUNKS: [[u8; 16]; 17] = [ + const BITSET_INDEX_CHUNKS: &'static [[u8; 16]; 17] = &[ [43, 43, 5, 34, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 5, 1], [43, 43, 5, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43], [43, 43, 39, 43, 43, 43, 43, 43, 17, 17, 62, 17, 42, 29, 24, 23], @@ -480,7 +490,7 @@ pub mod uppercase { [57, 19, 2, 18, 10, 47, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43], [57, 37, 17, 27, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43], ]; - static BITSET_CANONICAL: [u64; 43] = [ + const BITSET_CANONICAL: &'static [u64; 43] = &[ 0b0000011111111111111111111111111000000000000000000000000000000000, 0b0000000000111111111111111111111111111111111111111111111111111111, 0b0101010101010101010101010101010101010101010101010101010000000001, @@ -525,13 +535,14 @@ pub mod uppercase { 0b1111011111111111000000000000000000000000000000000000000000000000, 0b1111111100000000111111110000000000111111000000001111111100000000, ]; - static BITSET_MAPPING: [(u8, u8); 25] = [ + const BITSET_MAPPING: &'static [(u8, u8); 25] = &[ (0, 187), (0, 177), (0, 171), (0, 167), (0, 164), (0, 32), (0, 47), (0, 51), (0, 121), (0, 117), (0, 109), (1, 150), (1, 148), (1, 142), (1, 134), (1, 131), (1, 64), (2, 164), (2, 146), (2, 20), (3, 146), (3, 140), (3, 134), (4, 178), (4, 171), ]; - pub fn lookup(c: char) -> bool { + #[rustc_const_unstable(feature = "const_unicode_case_lookup", issue = "101400")] + pub const fn lookup(c: char) -> bool { super::bitset_search( c as u32, &BITSET_CHUNKS_MAP, @@ -544,18 +555,26 @@ pub mod uppercase { #[rustfmt::skip] pub mod white_space { - static SHORT_OFFSET_RUNS: [u32; 4] = [ - 5760, 18882560, 23080960, 40972289, - ]; - static OFFSETS: [u8; 21] = [ - 9, 5, 18, 1, 100, 1, 26, 1, 0, 1, 0, 11, 29, 2, 5, 1, 47, 1, 0, 1, 0, + static WHITESPACE_MAP: [u8; 256] = [ + 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, ]; + #[inline] pub fn lookup(c: char) -> bool { - super::skip_search( - c as u32, - &SHORT_OFFSET_RUNS, - &OFFSETS, - ) + match c as u32 >> 8 { + 0 => WHITESPACE_MAP[c as usize & 0xff] & 1 != 0, + 22 => c as u32 == 0x1680, + 32 => WHITESPACE_MAP[c as usize & 0xff] & 2 != 0, + 48 => c as u32 == 0x3000, + _ => false, + } } } diff --git a/library/core/tests/alloc.rs b/library/core/tests/alloc.rs index 8a5a06b34..3ceaeadce 100644 --- a/library/core/tests/alloc.rs +++ b/library/core/tests/alloc.rs @@ -1,4 +1,5 @@ use core::alloc::Layout; +use core::mem::size_of; use core::ptr::{self, NonNull}; #[test] @@ -13,6 +14,49 @@ fn const_unchecked_layout() { } #[test] +fn layout_round_up_to_align_edge_cases() { + const MAX_SIZE: usize = isize::MAX as usize; + + for shift in 0..usize::BITS { + let align = 1_usize << shift; + let edge = (MAX_SIZE + 1) - align; + let low = edge.saturating_sub(10); + let high = edge.saturating_add(10); + assert!(Layout::from_size_align(low, align).is_ok()); + assert!(Layout::from_size_align(high, align).is_err()); + for size in low..=high { + assert_eq!( + Layout::from_size_align(size, align).is_ok(), + size.next_multiple_of(align) <= MAX_SIZE, + ); + } + } +} + +#[test] +fn layout_array_edge_cases() { + for_type::<i64>(); + for_type::<[i32; 0b10101]>(); + for_type::<[u8; 0b1010101]>(); + + // Make sure ZSTs don't lead to divide-by-zero + assert_eq!(Layout::array::<()>(usize::MAX).unwrap(), Layout::from_size_align(0, 1).unwrap()); + + fn for_type<T>() { + const MAX_SIZE: usize = isize::MAX as usize; + + let edge = (MAX_SIZE + 1) / size_of::<T>(); + let low = edge.saturating_sub(10); + let high = edge.saturating_add(10); + assert!(Layout::array::<T>(low).is_ok()); + assert!(Layout::array::<T>(high).is_err()); + for n in low..=high { + assert_eq!(Layout::array::<T>(n).is_ok(), n * size_of::<T>() <= MAX_SIZE); + } + } +} + +#[test] fn layout_debug_shows_log2_of_alignment() { // `Debug` is not stable, but here's what it does right now let layout = Layout::from_size_align(24576, 8192).unwrap(); diff --git a/library/core/tests/any.rs b/library/core/tests/any.rs index 8ed0c8880..9538b8139 100644 --- a/library/core/tests/any.rs +++ b/library/core/tests/any.rs @@ -142,7 +142,7 @@ impl Provider for SomeConcreteType { demand .provide_ref::<String>(&self.some_string) .provide_ref::<str>(&self.some_string) - .provide_value::<String>(|| "bye".to_owned()); + .provide_value_with::<String>(|| "bye".to_owned()); } } diff --git a/library/core/tests/ascii.rs b/library/core/tests/ascii.rs index 6d2cf3e83..f5f2dd047 100644 --- a/library/core/tests/ascii.rs +++ b/library/core/tests/ascii.rs @@ -252,6 +252,23 @@ fn test_is_ascii_digit() { } #[test] +fn test_is_ascii_octdigit() { + assert_all!(is_ascii_octdigit, "", "01234567"); + assert_none!( + is_ascii_octdigit, + "abcdefghijklmnopqrstuvwxyz", + "ABCDEFGHIJKLMNOQPRSTUVWXYZ", + "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~", + " \t\n\x0c\r", + "\x00\x01\x02\x03\x04\x05\x06\x07", + "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f", + "\x10\x11\x12\x13\x14\x15\x16\x17", + "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f", + "\x7f", + ); +} + +#[test] fn test_is_ascii_hexdigit() { assert_all!(is_ascii_hexdigit, "", "0123456789", "abcdefABCDEF",); assert_none!( @@ -454,6 +471,7 @@ fn ascii_ctype_const() { is_ascii_lowercase => [true, false, false, false, false]; is_ascii_alphanumeric => [true, true, true, false, false]; is_ascii_digit => [false, false, true, false, false]; + is_ascii_octdigit => [false, false, false, false, false]; is_ascii_hexdigit => [true, true, true, false, false]; is_ascii_punctuation => [false, false, false, true, false]; is_ascii_graphic => [true, true, true, true, false]; diff --git a/library/core/tests/atomic.rs b/library/core/tests/atomic.rs index 13b12db20..94b031060 100644 --- a/library/core/tests/atomic.rs +++ b/library/core/tests/atomic.rs @@ -155,7 +155,7 @@ fn ptr_add_data() { assert_eq!(atom.fetch_ptr_sub(1, SeqCst), n.wrapping_add(1)); assert_eq!(atom.load(SeqCst), n); - let bytes_from_n = |b| n.cast::<u8>().wrapping_add(b).cast::<i64>(); + let bytes_from_n = |b| n.wrapping_byte_add(b); assert_eq!(atom.fetch_byte_add(1, SeqCst), n); assert_eq!(atom.load(SeqCst), bytes_from_n(1)); diff --git a/library/core/tests/const_ptr.rs b/library/core/tests/const_ptr.rs index 152fed803..d874f0831 100644 --- a/library/core/tests/const_ptr.rs +++ b/library/core/tests/const_ptr.rs @@ -3,7 +3,7 @@ const DATA: [u16; 2] = [u16::from_ne_bytes([0x01, 0x23]), u16::from_ne_bytes([0x const fn unaligned_ptr() -> *const u16 { // Since DATA.as_ptr() is aligned to two bytes, adding 1 byte to that produces an unaligned *const u16 - unsafe { (DATA.as_ptr() as *const u8).add(1) as *const u16 } + unsafe { DATA.as_ptr().byte_add(1) } } #[test] @@ -67,7 +67,7 @@ fn write() { const fn write_unaligned() -> [u16; 2] { let mut two_aligned = [0u16; 2]; unsafe { - let unaligned_ptr = (two_aligned.as_mut_ptr() as *mut u8).add(1) as *mut u16; + let unaligned_ptr = two_aligned.as_mut_ptr().byte_add(1); ptr::write_unaligned(unaligned_ptr, u16::from_ne_bytes([0x23, 0x45])); } two_aligned @@ -91,7 +91,7 @@ fn mut_ptr_write() { const fn write_unaligned() -> [u16; 2] { let mut two_aligned = [0u16; 2]; unsafe { - let unaligned_ptr = (two_aligned.as_mut_ptr() as *mut u8).add(1) as *mut u16; + let unaligned_ptr = two_aligned.as_mut_ptr().byte_add(1); unaligned_ptr.write_unaligned(u16::from_ne_bytes([0x23, 0x45])); } two_aligned diff --git a/library/core/tests/iter/adapters/array_chunks.rs b/library/core/tests/iter/adapters/array_chunks.rs new file mode 100644 index 000000000..4e9d89e1e --- /dev/null +++ b/library/core/tests/iter/adapters/array_chunks.rs @@ -0,0 +1,179 @@ +use core::cell::Cell; +use core::iter::{self, Iterator}; + +use super::*; + +#[test] +fn test_iterator_array_chunks_infer() { + let xs = [1, 1, 2, -2, 6, 0, 3, 1]; + for [a, b, c] in xs.iter().copied().array_chunks() { + assert_eq!(a + b + c, 4); + } +} + +#[test] +fn test_iterator_array_chunks_clone_and_drop() { + let count = Cell::new(0); + let mut it = (0..5).map(|_| CountDrop::new(&count)).array_chunks::<3>(); + assert_eq!(it.by_ref().count(), 1); + assert_eq!(count.get(), 3); + let mut it2 = it.clone(); + assert_eq!(count.get(), 3); + assert_eq!(it.into_remainder().unwrap().len(), 2); + assert_eq!(count.get(), 5); + assert!(it2.next().is_none()); + assert_eq!(it2.into_remainder().unwrap().len(), 2); + assert_eq!(count.get(), 7); +} + +#[test] +fn test_iterator_array_chunks_remainder() { + let mut it = (0..11).array_chunks::<4>(); + assert_eq!(it.next(), Some([0, 1, 2, 3])); + assert_eq!(it.next(), Some([4, 5, 6, 7])); + assert_eq!(it.next(), None); + assert_eq!(it.into_remainder().unwrap().as_slice(), &[8, 9, 10]); +} + +#[test] +fn test_iterator_array_chunks_size_hint() { + let it = (0..6).array_chunks::<1>(); + assert_eq!(it.size_hint(), (6, Some(6))); + + let it = (0..6).array_chunks::<3>(); + assert_eq!(it.size_hint(), (2, Some(2))); + + let it = (0..6).array_chunks::<5>(); + assert_eq!(it.size_hint(), (1, Some(1))); + + let it = (0..6).array_chunks::<7>(); + assert_eq!(it.size_hint(), (0, Some(0))); + + let it = (1..).array_chunks::<2>(); + assert_eq!(it.size_hint(), (usize::MAX / 2, None)); + + let it = (1..).filter(|x| x % 2 != 0).array_chunks::<2>(); + assert_eq!(it.size_hint(), (0, None)); +} + +#[test] +fn test_iterator_array_chunks_count() { + let it = (0..6).array_chunks::<1>(); + assert_eq!(it.count(), 6); + + let it = (0..6).array_chunks::<3>(); + assert_eq!(it.count(), 2); + + let it = (0..6).array_chunks::<5>(); + assert_eq!(it.count(), 1); + + let it = (0..6).array_chunks::<7>(); + assert_eq!(it.count(), 0); + + let it = (0..6).filter(|x| x % 2 == 0).array_chunks::<2>(); + assert_eq!(it.count(), 1); + + let it = iter::empty::<i32>().array_chunks::<2>(); + assert_eq!(it.count(), 0); + + let it = [(); usize::MAX].iter().array_chunks::<2>(); + assert_eq!(it.count(), usize::MAX / 2); +} + +#[test] +fn test_iterator_array_chunks_next_and_next_back() { + let mut it = (0..11).array_chunks::<3>(); + assert_eq!(it.next(), Some([0, 1, 2])); + assert_eq!(it.next_back(), Some([6, 7, 8])); + assert_eq!(it.next(), Some([3, 4, 5])); + assert_eq!(it.next_back(), None); + assert_eq!(it.next(), None); + assert_eq!(it.next_back(), None); + assert_eq!(it.next(), None); + assert_eq!(it.into_remainder().unwrap().as_slice(), &[9, 10]); +} + +#[test] +fn test_iterator_array_chunks_rev_remainder() { + let mut it = (0..11).array_chunks::<4>(); + { + let mut it = it.by_ref().rev(); + assert_eq!(it.next(), Some([4, 5, 6, 7])); + assert_eq!(it.next(), Some([0, 1, 2, 3])); + assert_eq!(it.next(), None); + assert_eq!(it.next(), None); + } + assert_eq!(it.into_remainder().unwrap().as_slice(), &[8, 9, 10]); +} + +#[test] +fn test_iterator_array_chunks_try_fold() { + let count = Cell::new(0); + let mut it = (0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>(); + let result: Result<_, ()> = it.by_ref().try_fold(0, |acc, _item| Ok(acc + 1)); + assert_eq!(result, Ok(3)); + assert_eq!(count.get(), 9); + drop(it); + assert_eq!(count.get(), 10); + + let count = Cell::new(0); + let mut it = (0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>(); + let result = it.by_ref().try_fold(0, |acc, _item| if acc < 2 { Ok(acc + 1) } else { Err(acc) }); + assert_eq!(result, Err(2)); + assert_eq!(count.get(), 9); + drop(it); + assert_eq!(count.get(), 9); +} + +#[test] +fn test_iterator_array_chunks_fold() { + let result = (1..11).array_chunks::<3>().fold(0, |acc, [a, b, c]| { + assert_eq!(acc + 1, a); + assert_eq!(acc + 2, b); + assert_eq!(acc + 3, c); + acc + 3 + }); + assert_eq!(result, 9); + + let count = Cell::new(0); + let result = + (0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>().fold(0, |acc, _item| acc + 1); + assert_eq!(result, 3); + assert_eq!(count.get(), 10); +} + +#[test] +fn test_iterator_array_chunks_try_rfold() { + let count = Cell::new(0); + let mut it = (0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>(); + let result: Result<_, ()> = it.try_rfold(0, |acc, _item| Ok(acc + 1)); + assert_eq!(result, Ok(3)); + assert_eq!(count.get(), 9); + drop(it); + assert_eq!(count.get(), 10); + + let count = Cell::new(0); + let mut it = (0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>(); + let result = it.try_rfold(0, |acc, _item| if acc < 2 { Ok(acc + 1) } else { Err(acc) }); + assert_eq!(result, Err(2)); + assert_eq!(count.get(), 9); + drop(it); + assert_eq!(count.get(), 10); +} + +#[test] +fn test_iterator_array_chunks_rfold() { + let result = (1..11).array_chunks::<3>().rfold(0, |acc, [a, b, c]| { + assert_eq!(10 - (acc + 1), c); + assert_eq!(10 - (acc + 2), b); + assert_eq!(10 - (acc + 3), a); + acc + 3 + }); + assert_eq!(result, 9); + + let count = Cell::new(0); + let result = + (0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>().rfold(0, |acc, _item| acc + 1); + assert_eq!(result, 3); + assert_eq!(count.get(), 10); +} diff --git a/library/core/tests/iter/adapters/by_ref_sized.rs b/library/core/tests/iter/adapters/by_ref_sized.rs new file mode 100644 index 000000000..a9c066f0e --- /dev/null +++ b/library/core/tests/iter/adapters/by_ref_sized.rs @@ -0,0 +1,20 @@ +use core::iter::*; + +#[test] +fn test_iterator_by_ref_sized() { + let a = ['a', 'b', 'c', 'd']; + + let mut s = String::from("Z"); + let mut it = a.iter().copied(); + ByRefSized(&mut it).take(2).for_each(|x| s.push(x)); + assert_eq!(s, "Zab"); + ByRefSized(&mut it).fold((), |(), x| s.push(x)); + assert_eq!(s, "Zabcd"); + + let mut s = String::from("Z"); + let mut it = a.iter().copied(); + ByRefSized(&mut it).rev().take(2).for_each(|x| s.push(x)); + assert_eq!(s, "Zdc"); + ByRefSized(&mut it).rfold((), |(), x| s.push(x)); + assert_eq!(s, "Zdcba"); +} diff --git a/library/core/tests/iter/adapters/flatten.rs b/library/core/tests/iter/adapters/flatten.rs index f8ab8c9d4..690fd0c21 100644 --- a/library/core/tests/iter/adapters/flatten.rs +++ b/library/core/tests/iter/adapters/flatten.rs @@ -168,3 +168,45 @@ fn test_trusted_len_flatten() { assert_trusted_len(&iter); assert_eq!(iter.size_hint(), (20, Some(20))); } + +#[test] +fn test_flatten_count() { + let mut it = once(0..10).chain(once(10..30)).chain(once(30..40)).flatten(); + + assert_eq!(it.clone().count(), 40); + it.advance_by(5).unwrap(); + assert_eq!(it.clone().count(), 35); + it.advance_back_by(5).unwrap(); + assert_eq!(it.clone().count(), 30); + it.advance_by(10).unwrap(); + assert_eq!(it.clone().count(), 20); + it.advance_back_by(8).unwrap(); + assert_eq!(it.clone().count(), 12); + it.advance_by(4).unwrap(); + assert_eq!(it.clone().count(), 8); + it.advance_back_by(5).unwrap(); + assert_eq!(it.clone().count(), 3); + it.advance_by(3).unwrap(); + assert_eq!(it.clone().count(), 0); +} + +#[test] +fn test_flatten_last() { + let mut it = once(0..10).chain(once(10..30)).chain(once(30..40)).flatten(); + + assert_eq!(it.clone().last(), Some(39)); + it.advance_by(5).unwrap(); // 5..40 + assert_eq!(it.clone().last(), Some(39)); + it.advance_back_by(5).unwrap(); // 5..35 + assert_eq!(it.clone().last(), Some(34)); + it.advance_by(10).unwrap(); // 15..35 + assert_eq!(it.clone().last(), Some(34)); + it.advance_back_by(8).unwrap(); // 15..27 + assert_eq!(it.clone().last(), Some(26)); + it.advance_by(4).unwrap(); // 19..27 + assert_eq!(it.clone().last(), Some(26)); + it.advance_back_by(5).unwrap(); // 19..22 + assert_eq!(it.clone().last(), Some(21)); + it.advance_by(3).unwrap(); // 22..22 + assert_eq!(it.clone().last(), None); +} diff --git a/library/core/tests/iter/adapters/mod.rs b/library/core/tests/iter/adapters/mod.rs index 567d9fe49..ffd5f3857 100644 --- a/library/core/tests/iter/adapters/mod.rs +++ b/library/core/tests/iter/adapters/mod.rs @@ -1,3 +1,5 @@ +mod array_chunks; +mod by_ref_sized; mod chain; mod cloned; mod copied; @@ -183,3 +185,25 @@ impl Clone for CountClone { ret } } + +#[derive(Debug, Clone)] +struct CountDrop<'a> { + dropped: bool, + count: &'a Cell<usize>, +} + +impl<'a> CountDrop<'a> { + pub fn new(count: &'a Cell<usize>) -> Self { + Self { dropped: false, count } + } +} + +impl Drop for CountDrop<'_> { + fn drop(&mut self) { + if self.dropped { + panic!("double drop"); + } + self.dropped = true; + self.count.set(self.count.get() + 1); + } +} diff --git a/library/core/tests/iter/adapters/skip.rs b/library/core/tests/iter/adapters/skip.rs index 65f235e86..754641834 100644 --- a/library/core/tests/iter/adapters/skip.rs +++ b/library/core/tests/iter/adapters/skip.rs @@ -201,3 +201,34 @@ fn test_skip_non_fused() { // advance it further. `Unfuse` tests that this doesn't happen by panicking in that scenario. let _ = non_fused.skip(20).next(); } + +#[test] +fn test_skip_non_fused_nth_overflow() { + let non_fused = Unfuse::new(0..10); + + // Ensures that calling skip and `nth` where the sum would overflow does not fail for non-fused + // iterators. + let _ = non_fused.skip(20).nth(usize::MAX); +} + +#[test] +fn test_skip_overflow_wrapping() { + // Test to ensure even on overflowing on `skip+nth` the correct amount of elements are yielded. + struct WrappingIterator(usize); + + impl Iterator for WrappingIterator { + type Item = usize; + + fn next(&mut self) -> core::option::Option<Self::Item> { + <Self as Iterator>::nth(self, 0) + } + + fn nth(&mut self, nth: usize) -> core::option::Option<Self::Item> { + self.0 = self.0.wrapping_add(nth.wrapping_add(1)); + Some(self.0) + } + } + + let wrap = WrappingIterator(0); + assert_eq!(wrap.skip(20).nth(usize::MAX), Some(20)); +} diff --git a/library/core/tests/lib.rs b/library/core/tests/lib.rs index db94368f6..51f858ade 100644 --- a/library/core/tests/lib.rs +++ b/library/core/tests/lib.rs @@ -2,11 +2,12 @@ #![feature(array_chunks)] #![feature(array_methods)] #![feature(array_windows)] -#![feature(bench_black_box)] +#![feature(bigint_helper_methods)] #![feature(cell_update)] #![feature(const_assume)] #![feature(const_black_box)] #![feature(const_bool_to_option)] +#![feature(const_caller_location)] #![feature(const_cell_into_inner)] #![feature(const_convert)] #![feature(const_heap)] @@ -14,11 +15,13 @@ #![feature(const_maybe_uninit_assume_init_read)] #![feature(const_nonnull_new)] #![feature(const_num_from_num)] +#![feature(const_pointer_byte_offsets)] #![feature(const_ptr_as_ref)] #![feature(const_ptr_read)] #![feature(const_ptr_write)] #![feature(const_trait_impl)] #![feature(const_likely)] +#![feature(const_location_fields)] #![feature(core_intrinsics)] #![feature(core_private_bignum)] #![feature(core_private_diy_float)] @@ -46,8 +49,8 @@ #![feature(slice_from_ptr_range)] #![feature(split_as_slice)] #![feature(maybe_uninit_uninit_array)] -#![feature(maybe_uninit_array_assume_init)] #![feature(maybe_uninit_write_slice)] +#![feature(maybe_uninit_uninit_array_transpose)] #![feature(min_specialization)] #![feature(numfmt)] #![feature(step_trait)] @@ -61,6 +64,7 @@ #![feature(slice_partition_dedup)] #![feature(int_log)] #![feature(iter_advance_by)] +#![feature(iter_array_chunks)] #![feature(iter_collect_into)] #![feature(iter_partition_in_place)] #![feature(iter_intersperse)] @@ -71,9 +75,10 @@ #![feature(iterator_try_reduce)] #![feature(const_mut_refs)] #![feature(const_pin)] +#![feature(const_waker)] #![feature(never_type)] #![feature(unwrap_infallible)] -#![feature(result_into_ok_or_err)] +#![feature(pointer_byte_offsets)] #![feature(portable_simd)] #![feature(ptr_metadata)] #![feature(once_cell)] @@ -90,12 +95,13 @@ #![feature(strict_provenance_atomic_ptr)] #![feature(trusted_random_access)] #![feature(unsize)] -#![feature(unzip_option)] #![feature(const_array_from_ref)] #![feature(const_slice_from_ref)] #![feature(waker_getters)] #![feature(slice_flatten)] #![feature(provide_any)] +#![feature(utf8_chunks)] +#![feature(is_ascii_octdigit)] #![deny(unsafe_op_in_unsafe_fn)] extern crate test; @@ -126,6 +132,7 @@ mod nonzero; mod num; mod ops; mod option; +mod panic; mod pattern; mod pin; mod pin_macro; diff --git a/library/core/tests/mem.rs b/library/core/tests/mem.rs index 6856d1a1f..0362e1c8a 100644 --- a/library/core/tests/mem.rs +++ b/library/core/tests/mem.rs @@ -130,7 +130,11 @@ fn test_transmute_copy_grow_panics() { payload .downcast::<&'static str>() .and_then(|s| { - if *s == "cannot transmute_copy if U is larger than T" { Ok(s) } else { Err(s) } + if *s == "cannot transmute_copy if Dst is larger than Src" { + Ok(s) + } else { + Err(s) + } }) .unwrap_or_else(|p| panic::resume_unwind(p)); } @@ -163,18 +167,18 @@ fn assume_init_good() { #[test] fn uninit_array_assume_init() { - let mut array: [MaybeUninit<i16>; 5] = MaybeUninit::uninit_array(); + let mut array = [MaybeUninit::<i16>::uninit(); 5]; array[0].write(3); array[1].write(1); array[2].write(4); array[3].write(1); array[4].write(5); - let array = unsafe { MaybeUninit::array_assume_init(array) }; + let array = unsafe { array.transpose().assume_init() }; assert_eq!(array, [3, 1, 4, 1, 5]); - let [] = unsafe { MaybeUninit::<!>::array_assume_init([]) }; + let [] = unsafe { [MaybeUninit::<!>::uninit(); 0].transpose().assume_init() }; } #[test] diff --git a/library/core/tests/num/int_log.rs b/library/core/tests/num/int_log.rs index dc3092e14..a1edb1a51 100644 --- a/library/core/tests/num/int_log.rs +++ b/library/core/tests/num/int_log.rs @@ -1,166 +1,196 @@ -//! This tests the `Integer::{log,log2,log10}` methods. These tests are in a +//! This tests the `Integer::{ilog,log2,log10}` methods. These tests are in a //! separate file because there's both a large number of them, and not all tests -//! can be run on Android. This is because in Android `log2` uses an imprecise +//! can be run on Android. This is because in Android `ilog2` uses an imprecise //! approximation:https://github.com/rust-lang/rust/blob/4825e12fc9c79954aa0fe18f5521efa6c19c7539/src/libstd/sys/unix/android.rs#L27-L53 #[test] -fn checked_log() { - assert_eq!(999u32.checked_log(10), Some(2)); - assert_eq!(1000u32.checked_log(10), Some(3)); - assert_eq!(555u32.checked_log(13), Some(2)); - assert_eq!(63u32.checked_log(4), Some(2)); - assert_eq!(64u32.checked_log(4), Some(3)); - assert_eq!(10460353203u64.checked_log(3), Some(21)); - assert_eq!(10460353202u64.checked_log(3), Some(20)); - assert_eq!(147808829414345923316083210206383297601u128.checked_log(3), Some(80)); - assert_eq!(147808829414345923316083210206383297600u128.checked_log(3), Some(79)); - assert_eq!(22528399544939174411840147874772641u128.checked_log(19683), Some(8)); - assert_eq!(22528399544939174411840147874772631i128.checked_log(19683), Some(7)); - - assert_eq!(0u8.checked_log(4), None); - assert_eq!(0u16.checked_log(4), None); - assert_eq!(0i8.checked_log(4), None); - assert_eq!(0i16.checked_log(4), None); +fn checked_ilog() { + assert_eq!(999u32.checked_ilog(10), Some(2)); + assert_eq!(1000u32.checked_ilog(10), Some(3)); + assert_eq!(555u32.checked_ilog(13), Some(2)); + assert_eq!(63u32.checked_ilog(4), Some(2)); + assert_eq!(64u32.checked_ilog(4), Some(3)); + assert_eq!(10460353203u64.checked_ilog(3), Some(21)); + assert_eq!(10460353202u64.checked_ilog(3), Some(20)); + assert_eq!(147808829414345923316083210206383297601u128.checked_ilog(3), Some(80)); + assert_eq!(147808829414345923316083210206383297600u128.checked_ilog(3), Some(79)); + assert_eq!(22528399544939174411840147874772641u128.checked_ilog(19683), Some(8)); + assert_eq!(22528399544939174411840147874772631i128.checked_ilog(19683), Some(7)); + + assert_eq!(0u8.checked_ilog(4), None); + assert_eq!(0u16.checked_ilog(4), None); + assert_eq!(0i8.checked_ilog(4), None); + assert_eq!(0i16.checked_ilog(4), None); #[cfg(not(miri))] // Miri is too slow for i in i16::MIN..=0 { - assert_eq!(i.checked_log(4), None); + assert_eq!(i.checked_ilog(4), None); } #[cfg(not(miri))] // Miri is too slow for i in 1..=i16::MAX { - assert_eq!(i.checked_log(13), Some((i as f32).log(13.0) as u32)); + assert_eq!(i.checked_ilog(13), Some((i as f32).log(13.0) as u32)); } #[cfg(not(miri))] // Miri is too slow for i in 1..=u16::MAX { - assert_eq!(i.checked_log(13), Some((i as f32).log(13.0) as u32)); + assert_eq!(i.checked_ilog(13), Some((i as f32).log(13.0) as u32)); } } #[test] -fn checked_log2() { - assert_eq!(5u32.checked_log2(), Some(2)); - assert_eq!(0u64.checked_log2(), None); - assert_eq!(128i32.checked_log2(), Some(7)); - assert_eq!((-55i16).checked_log2(), None); +fn checked_ilog2() { + assert_eq!(5u32.checked_ilog2(), Some(2)); + assert_eq!(0u64.checked_ilog2(), None); + assert_eq!(128i32.checked_ilog2(), Some(7)); + assert_eq!((-55i16).checked_ilog2(), None); - assert_eq!(0u8.checked_log2(), None); - assert_eq!(0u16.checked_log2(), None); - assert_eq!(0i8.checked_log2(), None); - assert_eq!(0i16.checked_log2(), None); + assert_eq!(0u8.checked_ilog2(), None); + assert_eq!(0u16.checked_ilog2(), None); + assert_eq!(0i8.checked_ilog2(), None); + assert_eq!(0i16.checked_ilog2(), None); for i in 1..=u8::MAX { - assert_eq!(i.checked_log2(), Some((i as f32).log2() as u32)); + assert_eq!(i.checked_ilog2(), Some((i as f32).log2() as u32)); } #[cfg(not(miri))] // Miri is too slow for i in 1..=u16::MAX { - // Guard against Android's imprecise f32::log2 implementation. + // Guard against Android's imprecise f32::ilog2 implementation. if i != 8192 && i != 32768 { - assert_eq!(i.checked_log2(), Some((i as f32).log2() as u32)); + assert_eq!(i.checked_ilog2(), Some((i as f32).log2() as u32)); } } for i in i8::MIN..=0 { - assert_eq!(i.checked_log2(), None); + assert_eq!(i.checked_ilog2(), None); } for i in 1..=i8::MAX { - assert_eq!(i.checked_log2(), Some((i as f32).log2() as u32)); + assert_eq!(i.checked_ilog2(), Some((i as f32).log2() as u32)); } #[cfg(not(miri))] // Miri is too slow for i in i16::MIN..=0 { - assert_eq!(i.checked_log2(), None); + assert_eq!(i.checked_ilog2(), None); } #[cfg(not(miri))] // Miri is too slow for i in 1..=i16::MAX { - // Guard against Android's imprecise f32::log2 implementation. + // Guard against Android's imprecise f32::ilog2 implementation. if i != 8192 { - assert_eq!(i.checked_log2(), Some((i as f32).log2() as u32)); + assert_eq!(i.checked_ilog2(), Some((i as f32).log2() as u32)); } } } -// Validate cases that fail on Android's imprecise float log2 implementation. +// Validate cases that fail on Android's imprecise float ilog2 implementation. #[test] #[cfg(not(target_os = "android"))] -fn checked_log2_not_android() { - assert_eq!(8192u16.checked_log2(), Some((8192f32).log2() as u32)); - assert_eq!(32768u16.checked_log2(), Some((32768f32).log2() as u32)); - assert_eq!(8192i16.checked_log2(), Some((8192f32).log2() as u32)); +fn checked_ilog2_not_android() { + assert_eq!(8192u16.checked_ilog2(), Some((8192f32).log2() as u32)); + assert_eq!(32768u16.checked_ilog2(), Some((32768f32).log2() as u32)); + assert_eq!(8192i16.checked_ilog2(), Some((8192f32).log2() as u32)); } #[test] -fn checked_log10() { - assert_eq!(0u8.checked_log10(), None); - assert_eq!(0u16.checked_log10(), None); - assert_eq!(0i8.checked_log10(), None); - assert_eq!(0i16.checked_log10(), None); +fn checked_ilog10() { + assert_eq!(0u8.checked_ilog10(), None); + assert_eq!(0u16.checked_ilog10(), None); + assert_eq!(0i8.checked_ilog10(), None); + assert_eq!(0i16.checked_ilog10(), None); #[cfg(not(miri))] // Miri is too slow for i in i16::MIN..=0 { - assert_eq!(i.checked_log10(), None); + assert_eq!(i.checked_ilog10(), None); } #[cfg(not(miri))] // Miri is too slow for i in 1..=i16::MAX { - assert_eq!(i.checked_log10(), Some((i as f32).log10() as u32)); + assert_eq!(i.checked_ilog10(), Some((i as f32).log10() as u32)); } #[cfg(not(miri))] // Miri is too slow for i in 1..=u16::MAX { - assert_eq!(i.checked_log10(), Some((i as f32).log10() as u32)); + assert_eq!(i.checked_ilog10(), Some((i as f32).log10() as u32)); } #[cfg(not(miri))] // Miri is too slow for i in 1..=100_000u32 { - assert_eq!(i.checked_log10(), Some((i as f32).log10() as u32)); + assert_eq!(i.checked_ilog10(), Some((i as f32).log10() as u32)); } } -macro_rules! log10_loop { - ($T:ty, $log10_max:expr) => { - assert_eq!(<$T>::MAX.log10(), $log10_max); - for i in 0..=$log10_max { +macro_rules! ilog10_loop { + ($T:ty, $ilog10_max:expr) => { + assert_eq!(<$T>::MAX.ilog10(), $ilog10_max); + for i in 0..=$ilog10_max { let p = (10 as $T).pow(i as u32); if p >= 10 { - assert_eq!((p - 9).log10(), i - 1); - assert_eq!((p - 1).log10(), i - 1); + assert_eq!((p - 9).ilog10(), i - 1); + assert_eq!((p - 1).ilog10(), i - 1); } - assert_eq!(p.log10(), i); - assert_eq!((p + 1).log10(), i); + assert_eq!(p.ilog10(), i); + assert_eq!((p + 1).ilog10(), i); if p >= 10 { - assert_eq!((p + 9).log10(), i); + assert_eq!((p + 9).ilog10(), i); } - // also check `x.log(10)` + // also check `x.ilog(10)` if p >= 10 { - assert_eq!((p - 9).log(10), i - 1); - assert_eq!((p - 1).log(10), i - 1); + assert_eq!((p - 9).ilog(10), i - 1); + assert_eq!((p - 1).ilog(10), i - 1); } - assert_eq!(p.log(10), i); - assert_eq!((p + 1).log(10), i); + assert_eq!(p.ilog(10), i); + assert_eq!((p + 1).ilog(10), i); if p >= 10 { - assert_eq!((p + 9).log(10), i); + assert_eq!((p + 9).ilog(10), i); } } }; } #[test] -fn log10_u8() { - log10_loop! { u8, 2 } +fn ilog10_u8() { + ilog10_loop! { u8, 2 } } #[test] -fn log10_u16() { - log10_loop! { u16, 4 } +fn ilog10_u16() { + ilog10_loop! { u16, 4 } } #[test] -fn log10_u32() { - log10_loop! { u32, 9 } +fn ilog10_u32() { + ilog10_loop! { u32, 9 } } #[test] -fn log10_u64() { - log10_loop! { u64, 19 } +fn ilog10_u64() { + ilog10_loop! { u64, 19 } } #[test] -fn log10_u128() { - log10_loop! { u128, 38 } +fn ilog10_u128() { + ilog10_loop! { u128, 38 } +} + +#[test] +#[should_panic(expected = "argument of integer logarithm must be positive")] +fn ilog2_of_0_panic() { + let _ = 0u32.ilog2(); +} + +#[test] +#[should_panic(expected = "argument of integer logarithm must be positive")] +fn ilog10_of_0_panic() { + let _ = 0u32.ilog10(); +} + +#[test] +#[should_panic(expected = "argument of integer logarithm must be positive")] +fn ilog3_of_0_panic() { + let _ = 0u32.ilog(3); +} + +#[test] +#[should_panic(expected = "base of integer logarithm must be at least 2")] +fn ilog0_of_1_panic() { + let _ = 1u32.ilog(0); +} + +#[test] +#[should_panic(expected = "base of integer logarithm must be at least 2")] +fn ilog1_of_1_panic() { + let _ = 1u32.ilog(1); } diff --git a/library/core/tests/num/int_macros.rs b/library/core/tests/num/int_macros.rs index 8b84a78e6..18c55e43a 100644 --- a/library/core/tests/num/int_macros.rs +++ b/library/core/tests/num/int_macros.rs @@ -338,6 +338,32 @@ macro_rules! int_module { assert_eq!(MIN.checked_next_multiple_of(-3), None); assert_eq!(MIN.checked_next_multiple_of(-1), Some(MIN)); } + + #[test] + fn test_carrying_add() { + assert_eq!($T::MAX.carrying_add(1, false), ($T::MIN, true)); + assert_eq!($T::MAX.carrying_add(0, true), ($T::MIN, true)); + assert_eq!($T::MAX.carrying_add(1, true), ($T::MIN + 1, true)); + assert_eq!($T::MAX.carrying_add(-1, false), ($T::MAX - 1, false)); + assert_eq!($T::MAX.carrying_add(-1, true), ($T::MAX, false)); // no intermediate overflow + assert_eq!($T::MIN.carrying_add(-1, false), ($T::MAX, true)); + assert_eq!($T::MIN.carrying_add(-1, true), ($T::MIN, false)); // no intermediate overflow + assert_eq!((0 as $T).carrying_add($T::MAX, true), ($T::MIN, true)); + assert_eq!((0 as $T).carrying_add($T::MIN, true), ($T::MIN + 1, false)); + } + + #[test] + fn test_borrowing_sub() { + assert_eq!($T::MIN.borrowing_sub(1, false), ($T::MAX, true)); + assert_eq!($T::MIN.borrowing_sub(0, true), ($T::MAX, true)); + assert_eq!($T::MIN.borrowing_sub(1, true), ($T::MAX - 1, true)); + assert_eq!($T::MIN.borrowing_sub(-1, false), ($T::MIN + 1, false)); + assert_eq!($T::MIN.borrowing_sub(-1, true), ($T::MIN, false)); // no intermediate overflow + assert_eq!($T::MAX.borrowing_sub(-1, false), ($T::MIN, true)); + assert_eq!($T::MAX.borrowing_sub(-1, true), ($T::MAX, false)); // no intermediate overflow + assert_eq!((0 as $T).borrowing_sub($T::MIN, false), ($T::MIN, true)); + assert_eq!((0 as $T).borrowing_sub($T::MIN, true), ($T::MAX, false)); + } } }; } diff --git a/library/core/tests/num/mod.rs b/library/core/tests/num/mod.rs index 49580cdcc..c79e909e4 100644 --- a/library/core/tests/num/mod.rs +++ b/library/core/tests/num/mod.rs @@ -172,7 +172,7 @@ fn test_can_not_overflow() { // Calcutate the string length for the smallest overflowing number: let max_len_string = format_radix(num, base as u128); - // Ensure that that string length is deemed to potentially overflow: + // Ensure that string length is deemed to potentially overflow: assert!(can_overflow::<$t>(base, &max_len_string)); } )*) diff --git a/library/core/tests/num/uint_macros.rs b/library/core/tests/num/uint_macros.rs index 93ae620c2..15ae9f232 100644 --- a/library/core/tests/num/uint_macros.rs +++ b/library/core/tests/num/uint_macros.rs @@ -230,6 +230,28 @@ macro_rules! uint_module { assert_eq!((1 as $T).checked_next_multiple_of(0), None); assert_eq!(MAX.checked_next_multiple_of(2), None); } + + #[test] + fn test_carrying_add() { + assert_eq!($T::MAX.carrying_add(1, false), (0, true)); + assert_eq!($T::MAX.carrying_add(0, true), (0, true)); + assert_eq!($T::MAX.carrying_add(1, true), (1, true)); + + assert_eq!($T::MIN.carrying_add($T::MAX, false), ($T::MAX, false)); + assert_eq!($T::MIN.carrying_add(0, true), (1, false)); + assert_eq!($T::MIN.carrying_add($T::MAX, true), (0, true)); + } + + #[test] + fn test_borrowing_sub() { + assert_eq!($T::MIN.borrowing_sub(1, false), ($T::MAX, true)); + assert_eq!($T::MIN.borrowing_sub(0, true), ($T::MAX, true)); + assert_eq!($T::MIN.borrowing_sub(1, true), ($T::MAX - 1, true)); + + assert_eq!($T::MAX.borrowing_sub($T::MAX, false), (0, false)); + assert_eq!($T::MAX.borrowing_sub(0, true), ($T::MAX - 1, false)); + assert_eq!($T::MAX.borrowing_sub($T::MAX, true), ($T::MAX, true)); + } } }; } diff --git a/library/core/tests/num/wrapping.rs b/library/core/tests/num/wrapping.rs index 8ded139a1..c5a719883 100644 --- a/library/core/tests/num/wrapping.rs +++ b/library/core/tests/num/wrapping.rs @@ -75,8 +75,6 @@ wrapping_test!(test_wrapping_u64, u64, u64::MIN, u64::MAX); wrapping_test!(test_wrapping_u128, u128, u128::MIN, u128::MAX); wrapping_test!(test_wrapping_usize, usize, usize::MIN, usize::MAX); -// Don't warn about overflowing ops on 32-bit platforms -#[cfg_attr(target_pointer_width = "32", allow(const_err))] #[test] fn wrapping_int_api() { assert_eq!(i8::MAX.wrapping_add(1), i8::MIN); diff --git a/library/core/tests/option.rs b/library/core/tests/option.rs index 9f5e537dc..f36f7c268 100644 --- a/library/core/tests/option.rs +++ b/library/core/tests/option.rs @@ -57,6 +57,7 @@ fn test_get_resource() { } #[test] +#[cfg_attr(not(bootstrap), allow(for_loops_over_fallibles))] fn test_option_dance() { let x = Some(()); let mut y = Some(5); diff --git a/library/core/tests/panic.rs b/library/core/tests/panic.rs new file mode 100644 index 000000000..24b6c56b3 --- /dev/null +++ b/library/core/tests/panic.rs @@ -0,0 +1 @@ +mod location; diff --git a/library/core/tests/panic/location.rs b/library/core/tests/panic/location.rs new file mode 100644 index 000000000..d20241d83 --- /dev/null +++ b/library/core/tests/panic/location.rs @@ -0,0 +1,31 @@ +use core::panic::Location; + +// Note: Some of the following tests depend on the source location, +// so please be careful when editing this file. + +#[test] +fn location_const_caller() { + const _CALLER_REFERENCE: &Location<'static> = Location::caller(); + const _CALLER: Location<'static> = *Location::caller(); +} + +#[test] +fn location_const_file() { + const CALLER: &Location<'static> = Location::caller(); + const FILE: &str = CALLER.file(); + assert_eq!(FILE, file!()); +} + +#[test] +fn location_const_line() { + const CALLER: &Location<'static> = Location::caller(); + const LINE: u32 = CALLER.line(); + assert_eq!(LINE, 21); +} + +#[test] +fn location_const_column() { + const CALLER: &Location<'static> = Location::caller(); + const COLUMN: u32 = CALLER.column(); + assert_eq!(COLUMN, 40); +} diff --git a/library/core/tests/ptr.rs b/library/core/tests/ptr.rs index 12861794c..97a369810 100644 --- a/library/core/tests/ptr.rs +++ b/library/core/tests/ptr.rs @@ -650,7 +650,7 @@ fn thin_box() { .unwrap_or_else(|| handle_alloc_error(layout)) .cast::<DynMetadata<T>>(); ptr.as_ptr().write(meta); - ptr.cast::<u8>().as_ptr().add(offset).cast::<Value>().write(value); + ptr.as_ptr().byte_add(offset).cast::<Value>().write(value); Self { ptr, phantom: PhantomData } } } diff --git a/library/core/tests/result.rs b/library/core/tests/result.rs index 103e8cc3a..50926da3c 100644 --- a/library/core/tests/result.rs +++ b/library/core/tests/result.rs @@ -96,15 +96,6 @@ fn test_unwrap_or() { } #[test] -fn test_ok_or_err() { - let ok: Result<isize, isize> = Ok(100); - let err: Result<isize, isize> = Err(200); - - assert_eq!(ok.into_ok_or_err(), 100); - assert_eq!(err.into_ok_or_err(), 200); -} - -#[test] fn test_unwrap_or_else() { fn handler(msg: &'static str) -> isize { if msg == "I got this." { 50 } else { panic!("BadBad") } diff --git a/library/core/tests/slice.rs b/library/core/tests/slice.rs index 0656109e9..9e1fbea79 100644 --- a/library/core/tests/slice.rs +++ b/library/core/tests/slice.rs @@ -1197,7 +1197,6 @@ fn chunks_mut_are_send_and_sync() { use std::slice::{ChunksExactMut, ChunksMut, RChunksExactMut, RChunksMut}; use std::sync::MutexGuard; - #[allow(unused)] fn assert_send_and_sync() where ChunksMut<'static, Cell<i32>>: Send, @@ -1210,6 +1209,8 @@ fn chunks_mut_are_send_and_sync() { RChunksExactMut<'static, MutexGuard<'static, u32>>: Sync, { } + + assert_send_and_sync(); } #[test] @@ -1283,7 +1284,6 @@ fn test_windows_zip() { } #[test] -#[allow(const_err)] fn test_iter_ref_consistency() { use std::fmt::Debug; diff --git a/library/core/tests/str_lossy.rs b/library/core/tests/str_lossy.rs index d4b47a470..9d3f0b65f 100644 --- a/library/core/tests/str_lossy.rs +++ b/library/core/tests/str_lossy.rs @@ -1,85 +1,85 @@ -use core::str::lossy::*; +use core::str::Utf8Chunks; #[test] fn chunks() { - let mut iter = Utf8Lossy::from_bytes(b"hello").chunks(); - assert_eq!(Some(Utf8LossyChunk { valid: "hello", broken: b"" }), iter.next()); - assert_eq!(None, iter.next()); + macro_rules! assert_chunks { + ( $string:expr, $(($valid:expr, $invalid:expr)),* $(,)? ) => {{ + let mut iter = Utf8Chunks::new($string); + $( + let chunk = iter.next().expect("missing chunk"); + assert_eq!($valid, chunk.valid()); + assert_eq!($invalid, chunk.invalid()); + )* + assert_eq!(None, iter.next()); + }}; + } - let mut iter = Utf8Lossy::from_bytes("ศไทย中华Việt Nam".as_bytes()).chunks(); - assert_eq!(Some(Utf8LossyChunk { valid: "ศไทย中华Việt Nam", broken: b"" }), iter.next()); - assert_eq!(None, iter.next()); - - let mut iter = Utf8Lossy::from_bytes(b"Hello\xC2 There\xFF Goodbye").chunks(); - assert_eq!(Some(Utf8LossyChunk { valid: "Hello", broken: b"\xC2" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: " There", broken: b"\xFF" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: " Goodbye", broken: b"" }), iter.next()); - assert_eq!(None, iter.next()); - - let mut iter = Utf8Lossy::from_bytes(b"Hello\xC0\x80 There\xE6\x83 Goodbye").chunks(); - assert_eq!(Some(Utf8LossyChunk { valid: "Hello", broken: b"\xC0" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\x80" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: " There", broken: b"\xE6\x83" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: " Goodbye", broken: b"" }), iter.next()); - assert_eq!(None, iter.next()); - - let mut iter = Utf8Lossy::from_bytes(b"\xF5foo\xF5\x80bar").chunks(); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\xF5" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "foo", broken: b"\xF5" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\x80" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "bar", broken: b"" }), iter.next()); - assert_eq!(None, iter.next()); - - let mut iter = Utf8Lossy::from_bytes(b"\xF1foo\xF1\x80bar\xF1\x80\x80baz").chunks(); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\xF1" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "foo", broken: b"\xF1\x80" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "bar", broken: b"\xF1\x80\x80" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "baz", broken: b"" }), iter.next()); - assert_eq!(None, iter.next()); - - let mut iter = Utf8Lossy::from_bytes(b"\xF4foo\xF4\x80bar\xF4\xBFbaz").chunks(); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\xF4" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "foo", broken: b"\xF4\x80" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "bar", broken: b"\xF4" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\xBF" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "baz", broken: b"" }), iter.next()); - assert_eq!(None, iter.next()); - - let mut iter = Utf8Lossy::from_bytes(b"\xF0\x80\x80\x80foo\xF0\x90\x80\x80bar").chunks(); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\xF0" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\x80" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\x80" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\x80" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "foo\u{10000}bar", broken: b"" }), iter.next()); - assert_eq!(None, iter.next()); + assert_chunks!(b"hello", ("hello", b"")); + assert_chunks!("ศไทย中华Việt Nam".as_bytes(), ("ศไทย中华Việt Nam", b"")); + assert_chunks!( + b"Hello\xC2 There\xFF Goodbye", + ("Hello", b"\xC2"), + (" There", b"\xFF"), + (" Goodbye", b""), + ); + assert_chunks!( + b"Hello\xC0\x80 There\xE6\x83 Goodbye", + ("Hello", b"\xC0"), + ("", b"\x80"), + (" There", b"\xE6\x83"), + (" Goodbye", b""), + ); + assert_chunks!( + b"\xF5foo\xF5\x80bar", + ("", b"\xF5"), + ("foo", b"\xF5"), + ("", b"\x80"), + ("bar", b""), + ); + assert_chunks!( + b"\xF1foo\xF1\x80bar\xF1\x80\x80baz", + ("", b"\xF1"), + ("foo", b"\xF1\x80"), + ("bar", b"\xF1\x80\x80"), + ("baz", b""), + ); + assert_chunks!( + b"\xF4foo\xF4\x80bar\xF4\xBFbaz", + ("", b"\xF4"), + ("foo", b"\xF4\x80"), + ("bar", b"\xF4"), + ("", b"\xBF"), + ("baz", b""), + ); + assert_chunks!( + b"\xF0\x80\x80\x80foo\xF0\x90\x80\x80bar", + ("", b"\xF0"), + ("", b"\x80"), + ("", b"\x80"), + ("", b"\x80"), + ("foo\u{10000}bar", b""), + ); // surrogates - let mut iter = Utf8Lossy::from_bytes(b"\xED\xA0\x80foo\xED\xBF\xBFbar").chunks(); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\xED" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\xA0" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\x80" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "foo", broken: b"\xED" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\xBF" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "", broken: b"\xBF" }), iter.next()); - assert_eq!(Some(Utf8LossyChunk { valid: "bar", broken: b"" }), iter.next()); - assert_eq!(None, iter.next()); -} - -#[test] -fn display() { - assert_eq!( - "Hello\u{FFFD}\u{FFFD} There\u{FFFD} Goodbye", - &Utf8Lossy::from_bytes(b"Hello\xC0\x80 There\xE6\x83 Goodbye").to_string() + assert_chunks!( + b"\xED\xA0\x80foo\xED\xBF\xBFbar", + ("", b"\xED"), + ("", b"\xA0"), + ("", b"\x80"), + ("foo", b"\xED"), + ("", b"\xBF"), + ("", b"\xBF"), + ("bar", b""), ); } #[test] fn debug() { assert_eq!( - "\"Hello\\xc0\\x80 There\\xe6\\x83 Goodbye\\u{10d4ea}\"", + "\"Hello\\xC0\\x80 There\\xE6\\x83 Goodbye\\u{10d4ea}\"", &format!( "{:?}", - Utf8Lossy::from_bytes(b"Hello\xC0\x80 There\xE6\x83 Goodbye\xf4\x8d\x93\xaa") - ) + Utf8Chunks::new(b"Hello\xC0\x80 There\xE6\x83 Goodbye\xf4\x8d\x93\xaa").debug(), + ), ); } diff --git a/library/core/tests/task.rs b/library/core/tests/task.rs index d71fef9e5..56be30e92 100644 --- a/library/core/tests/task.rs +++ b/library/core/tests/task.rs @@ -1,4 +1,4 @@ -use core::task::Poll; +use core::task::{Context, Poll, RawWaker, RawWakerVTable, Waker}; #[test] fn poll_const() { @@ -12,3 +12,18 @@ fn poll_const() { const IS_PENDING: bool = POLL.is_pending(); assert!(IS_PENDING); } + +#[test] +fn waker_const() { + const VOID_TABLE: RawWakerVTable = RawWakerVTable::new(|_| VOID_WAKER, |_| {}, |_| {}, |_| {}); + + const VOID_WAKER: RawWaker = RawWaker::new(&(), &VOID_TABLE); + + static WAKER: Waker = unsafe { Waker::from_raw(VOID_WAKER) }; + + static CONTEXT: Context<'static> = Context::from_waker(&WAKER); + + static WAKER_REF: &'static Waker = CONTEXT.waker(); + + WAKER_REF.wake_by_ref(); +} diff --git a/library/core/tests/time.rs b/library/core/tests/time.rs index fe2d2f241..a05128de4 100644 --- a/library/core/tests/time.rs +++ b/library/core/tests/time.rs @@ -197,9 +197,31 @@ fn correct_sum() { #[test] fn debug_formatting_extreme_values() { assert_eq!( - format!("{:?}", Duration::new(18_446_744_073_709_551_615, 123_456_789)), + format!("{:?}", Duration::new(u64::MAX, 123_456_789)), "18446744073709551615.123456789s" ); + assert_eq!(format!("{:.0?}", Duration::MAX), "18446744073709551616s"); + assert_eq!(format!("{:.0?}", Duration::new(u64::MAX, 500_000_000)), "18446744073709551616s"); + assert_eq!(format!("{:.0?}", Duration::new(u64::MAX, 499_999_999)), "18446744073709551615s"); + assert_eq!( + format!("{:.3?}", Duration::new(u64::MAX, 999_500_000)), + "18446744073709551616.000s" + ); + assert_eq!( + format!("{:.3?}", Duration::new(u64::MAX, 999_499_999)), + "18446744073709551615.999s" + ); + assert_eq!( + format!("{:.8?}", Duration::new(u64::MAX, 999_999_995)), + "18446744073709551616.00000000s" + ); + assert_eq!( + format!("{:.8?}", Duration::new(u64::MAX, 999_999_994)), + "18446744073709551615.99999999s" + ); + assert_eq!(format!("{:21.0?}", Duration::MAX), "18446744073709551616s"); + assert_eq!(format!("{:22.0?}", Duration::MAX), "18446744073709551616s "); + assert_eq!(format!("{:24.0?}", Duration::MAX), "18446744073709551616s "); } #[test] @@ -445,3 +467,11 @@ fn duration_const() { const SATURATING_MUL: Duration = MAX.saturating_mul(2); assert_eq!(SATURATING_MUL, MAX); } + +#[test] +fn from_neg_zero() { + assert_eq!(Duration::try_from_secs_f32(-0.0), Ok(Duration::ZERO)); + assert_eq!(Duration::try_from_secs_f64(-0.0), Ok(Duration::ZERO)); + assert_eq!(Duration::from_secs_f32(-0.0), Duration::ZERO); + assert_eq!(Duration::from_secs_f64(-0.0), Duration::ZERO); +} |