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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/rust/owning_ref | |
parent | Initial commit. (diff) | |
download | firefox-esr-upstream.tar.xz firefox-esr-upstream.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/owning_ref')
-rw-r--r-- | third_party/rust/owning_ref/.cargo-checksum.json | 1 | ||||
-rw-r--r-- | third_party/rust/owning_ref/CHANGELOG.md | 8 | ||||
-rw-r--r-- | third_party/rust/owning_ref/Cargo.toml | 24 | ||||
-rw-r--r-- | third_party/rust/owning_ref/LICENSE | 21 | ||||
-rw-r--r-- | third_party/rust/owning_ref/README.md | 64 | ||||
-rw-r--r-- | third_party/rust/owning_ref/src/lib.rs | 2016 |
6 files changed, 2134 insertions, 0 deletions
diff --git a/third_party/rust/owning_ref/.cargo-checksum.json b/third_party/rust/owning_ref/.cargo-checksum.json new file mode 100644 index 0000000000..274171be15 --- /dev/null +++ b/third_party/rust/owning_ref/.cargo-checksum.json @@ -0,0 +1 @@ +{"files":{"CHANGELOG.md":"9a3880e4d5435ca03c0197c45d4ce6b6db6d3fb7eda855f297bafc2ec28af836","Cargo.toml":"91184e6b143ddf621fe7e6757fb28d8eb4c0e01f541fbd0dc440bf076ebfd20d","LICENSE":"90bc15ed094593083fd129fdd1a03607be80fe8839c5564616a5961ab7f7a194","README.md":"0dfea39ad1662ed0a61bb1453eafc207a53dfe577e7846c87d3a5161574fdb12","src/lib.rs":"2e423e210bf2e3ee5e4c426b9a3c9b7756fc434beff1ccf9afa48704e4ac993d"},"package":"6ff55baddef9e4ad00f88b6c743a2a8062d4c6ade126c2a528644b8e444d52ce"}
\ No newline at end of file diff --git a/third_party/rust/owning_ref/CHANGELOG.md b/third_party/rust/owning_ref/CHANGELOG.md new file mode 100644 index 0000000000..a5d24e8c82 --- /dev/null +++ b/third_party/rust/owning_ref/CHANGELOG.md @@ -0,0 +1,8 @@ +# Changelog + +## [0.4.1] - 2020-02-27 +### Added +- `map_with_owner` (#51) + +### Changed +- Use dyn for trait objects (#53) diff --git a/third_party/rust/owning_ref/Cargo.toml b/third_party/rust/owning_ref/Cargo.toml new file mode 100644 index 0000000000..057fd5c1bb --- /dev/null +++ b/third_party/rust/owning_ref/Cargo.toml @@ -0,0 +1,24 @@ +# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO +# +# When uploading crates to the registry Cargo will automatically +# "normalize" Cargo.toml files for maximal compatibility +# with all versions of Cargo and also rewrite `path` dependencies +# to registry (e.g., crates.io) dependencies +# +# If you believe there's an error in this file please file an +# issue against the rust-lang/cargo repository. If you're +# editing this file be aware that the upstream Cargo.toml +# will likely look very different (and much more reasonable) + +[package] +name = "owning_ref" +version = "0.4.1" +authors = ["Marvin Löbel <loebel.marvin@gmail.com>"] +description = "A library for creating references that carry their owner with them." +documentation = "http://kimundi.github.io/owning-ref-rs/owning_ref/index.html" +readme = "README.md" +keywords = ["reference", "sibling", "field", "owning"] +license = "MIT" +repository = "https://github.com/Kimundi/owning-ref-rs" +[dependencies.stable_deref_trait] +version = "1.0.0" diff --git a/third_party/rust/owning_ref/LICENSE b/third_party/rust/owning_ref/LICENSE new file mode 100644 index 0000000000..dff72d1e43 --- /dev/null +++ b/third_party/rust/owning_ref/LICENSE @@ -0,0 +1,21 @@ +The MIT License (MIT) + +Copyright (c) 2015 Marvin Löbel + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. diff --git a/third_party/rust/owning_ref/README.md b/third_party/rust/owning_ref/README.md new file mode 100644 index 0000000000..ad32ac24fd --- /dev/null +++ b/third_party/rust/owning_ref/README.md @@ -0,0 +1,64 @@ +[![Build Status](https://travis-ci.org/Kimundi/owning-ref-rs.svg)](https://travis-ci.org/Kimundi/owning-ref-rs) +[![Crate](https://img.shields.io/crates/v/owning_ref.svg)](https://crates.io/crates/owning_ref) +[![Docs](https://docs.rs/owning_ref/badge.svg)](https://docs.rs/owning_ref) + +owning-ref-rs +============== + +A library for creating references that carry their owner with them. + +This can sometimes be useful because Rust borrowing rules normally prevent +moving a type that has been borrowed from. For example, this kind of code gets rejected: + +```rust +fn return_owned_and_referenced<'a>() -> (Vec<u8>, &'a [u8]) { + let v = vec![1, 2, 3, 4]; + let s = &v[1..3]; + (v, s) +} +``` + +This library enables this safe usage by keeping the owner and the reference +bundled together in a wrapper type that ensure that lifetime constraint: + +```rust +fn return_owned_and_referenced() -> OwningRef<Vec<u8>, [u8]> { + let v = vec![1, 2, 3, 4]; + let or = OwningRef::new(v); + let or = or.map(|v| &v[1..3]); + or +} +``` + +## Getting Started + +To get started, add the following to `Cargo.toml`. + +```toml +owning_ref = "0.4.1" +``` + +...and see the [docs](http://kimundi.github.io/owning-ref-rs/owning_ref/index.html) for how to use it. + + +## Example + +```rust +extern crate owning_ref; +use owning_ref::BoxRef; + +fn main() { + // Create an array owned by a Box. + let arr = Box::new([1, 2, 3, 4]) as Box<[i32]>; + + // Transfer into a BoxRef. + let arr: BoxRef<[i32]> = BoxRef::new(arr); + assert_eq!(&*arr, &[1, 2, 3, 4]); + + // We can slice the array without losing ownership or changing type. + let arr: BoxRef<[i32]> = arr.map(|arr| &arr[1..3]); + assert_eq!(&*arr, &[2, 3]); + + // Also works for Arc, Rc, String and Vec! +} +``` diff --git a/third_party/rust/owning_ref/src/lib.rs b/third_party/rust/owning_ref/src/lib.rs new file mode 100644 index 0000000000..fa2f15a220 --- /dev/null +++ b/third_party/rust/owning_ref/src/lib.rs @@ -0,0 +1,2016 @@ +#![warn(missing_docs)] + +/*! +# An owning reference. + +This crate provides the _owning reference_ types `OwningRef` and `OwningRefMut` +that enables it to bundle a reference together with the owner of the data it points to. +This allows moving and dropping of a `OwningRef` without needing to recreate the reference. + +This can sometimes be useful because Rust borrowing rules normally prevent +moving a type that has been moved from. For example, this kind of code gets rejected: + +```rust,ignore +fn return_owned_and_referenced<'a>() -> (Vec<u8>, &'a [u8]) { + let v = vec![1, 2, 3, 4]; + let s = &v[1..3]; + (v, s) +} +``` + +Even though, from a memory-layout point of view, this can be entirely safe +if the new location of the vector still lives longer than the lifetime `'a` +of the reference because the backing allocation of the vector does not change. + +This library enables this safe usage by keeping the owner and the reference +bundled together in a wrapper type that ensure that lifetime constraint: + +```rust +# extern crate owning_ref; +# use owning_ref::OwningRef; +# fn main() { +fn return_owned_and_referenced() -> OwningRef<Vec<u8>, [u8]> { + let v = vec![1, 2, 3, 4]; + let or = OwningRef::new(v); + let or = or.map(|v| &v[1..3]); + or +} +# } +``` + +It works by requiring owner types to dereference to stable memory locations +and preventing mutable access to root containers, which in practice requires heap allocation +as provided by `Box<T>`, `Rc<T>`, etc. + +Also provided are typedefs for common owner type combinations, +which allow for less verbose type signatures. For example, `BoxRef<T>` instead of `OwningRef<Box<T>, T>`. + +The crate also provides the more advanced `OwningHandle` type, +which allows more freedom in bundling a dependent handle object +along with the data it depends on, at the cost of some unsafe needed in the API. +See the documentation around `OwningHandle` for more details. + +# Examples + +## Basics + +``` +extern crate owning_ref; +use owning_ref::BoxRef; + +fn main() { + // Create an array owned by a Box. + let arr = Box::new([1, 2, 3, 4]) as Box<[i32]>; + + // Transfer into a BoxRef. + let arr: BoxRef<[i32]> = BoxRef::new(arr); + assert_eq!(&*arr, &[1, 2, 3, 4]); + + // We can slice the array without losing ownership or changing type. + let arr: BoxRef<[i32]> = arr.map(|arr| &arr[1..3]); + assert_eq!(&*arr, &[2, 3]); + + // Also works for Arc, Rc, String and Vec! +} +``` + +## Caching a reference to a struct field + +``` +extern crate owning_ref; +use owning_ref::BoxRef; + +fn main() { + struct Foo { + tag: u32, + x: u16, + y: u16, + z: u16, + } + let foo = Foo { tag: 1, x: 100, y: 200, z: 300 }; + + let or = BoxRef::new(Box::new(foo)).map(|foo| { + match foo.tag { + 0 => &foo.x, + 1 => &foo.y, + 2 => &foo.z, + _ => panic!(), + } + }); + + assert_eq!(*or, 200); +} +``` + +## Caching a reference to an entry in a vector + +``` +extern crate owning_ref; +use owning_ref::VecRef; + +fn main() { + let v = VecRef::new(vec![1, 2, 3, 4, 5]).map(|v| &v[3]); + assert_eq!(*v, 4); +} +``` + +## Caching a subslice of a String + +``` +extern crate owning_ref; +use owning_ref::StringRef; + +fn main() { + let s = StringRef::new("hello world".to_owned()) + .map(|s| s.split(' ').nth(1).unwrap()); + + assert_eq!(&*s, "world"); +} +``` + +## Reference counted slices that share ownership of the backing storage + +``` +extern crate owning_ref; +use owning_ref::RcRef; +use std::rc::Rc; + +fn main() { + let rc: RcRef<[i32]> = RcRef::new(Rc::new([1, 2, 3, 4]) as Rc<[i32]>); + assert_eq!(&*rc, &[1, 2, 3, 4]); + + let rc_a: RcRef<[i32]> = rc.clone().map(|s| &s[0..2]); + let rc_b = rc.clone().map(|s| &s[1..3]); + let rc_c = rc.clone().map(|s| &s[2..4]); + assert_eq!(&*rc_a, &[1, 2]); + assert_eq!(&*rc_b, &[2, 3]); + assert_eq!(&*rc_c, &[3, 4]); + + let rc_c_a = rc_c.clone().map(|s| &s[1]); + assert_eq!(&*rc_c_a, &4); +} +``` + +## Atomic reference counted slices that share ownership of the backing storage + +``` +extern crate owning_ref; +use owning_ref::ArcRef; +use std::sync::Arc; + +fn main() { + use std::thread; + + fn par_sum(rc: ArcRef<[i32]>) -> i32 { + if rc.len() == 0 { + return 0; + } else if rc.len() == 1 { + return rc[0]; + } + let mid = rc.len() / 2; + let left = rc.clone().map(|s| &s[..mid]); + let right = rc.map(|s| &s[mid..]); + + let left = thread::spawn(move || par_sum(left)); + let right = thread::spawn(move || par_sum(right)); + + left.join().unwrap() + right.join().unwrap() + } + + let rc: Arc<[i32]> = Arc::new([1, 2, 3, 4]); + let rc: ArcRef<[i32]> = rc.into(); + + assert_eq!(par_sum(rc), 10); +} +``` + +## References into RAII locks + +``` +extern crate owning_ref; +use owning_ref::RefRef; +use std::cell::{RefCell, Ref}; + +fn main() { + let refcell = RefCell::new((1, 2, 3, 4)); + // Also works with Mutex and RwLock + + let refref = { + let refref = RefRef::new(refcell.borrow()).map(|x| &x.3); + assert_eq!(*refref, 4); + + // We move the RAII lock and the reference to one of + // the subfields in the data it guards here: + refref + }; + + assert_eq!(*refref, 4); + + drop(refref); + + assert_eq!(*refcell.borrow(), (1, 2, 3, 4)); +} +``` + +## Mutable reference + +When the owned container implements `DerefMut`, it is also possible to make +a _mutable owning reference_. (E.g. with `Box`, `RefMut`, `MutexGuard`) + +``` +extern crate owning_ref; +use owning_ref::RefMutRefMut; +use std::cell::{RefCell, RefMut}; + +fn main() { + let refcell = RefCell::new((1, 2, 3, 4)); + + let mut refmut_refmut = { + let mut refmut_refmut = RefMutRefMut::new(refcell.borrow_mut()).map_mut(|x| &mut x.3); + assert_eq!(*refmut_refmut, 4); + *refmut_refmut *= 2; + + refmut_refmut + }; + + assert_eq!(*refmut_refmut, 8); + *refmut_refmut *= 2; + + drop(refmut_refmut); + + assert_eq!(*refcell.borrow(), (1, 2, 3, 16)); +} +``` +*/ + +extern crate stable_deref_trait; +pub use stable_deref_trait::{StableDeref as StableAddress, CloneStableDeref as CloneStableAddress}; + +/// An owning reference. +/// +/// This wraps an owner `O` and a reference `&T` pointing +/// at something reachable from `O::Target` while keeping +/// the ability to move `self` around. +/// +/// The owner is usually a pointer that points at some base type. +/// +/// For more details and examples, see the module and method docs. +pub struct OwningRef<O, T: ?Sized> { + owner: O, + reference: *const T, +} + +/// An mutable owning reference. +/// +/// This wraps an owner `O` and a reference `&mut T` pointing +/// at something reachable from `O::Target` while keeping +/// the ability to move `self` around. +/// +/// The owner is usually a pointer that points at some base type. +/// +/// For more details and examples, see the module and method docs. +pub struct OwningRefMut<O, T: ?Sized> { + owner: O, + reference: *mut T, +} + +/// Helper trait for an erased concrete type an owner dereferences to. +/// This is used in form of a trait object for keeping +/// something around to (virtually) call the destructor. +pub trait Erased {} +impl<T> Erased for T {} + +/// Helper trait for erasing the concrete type of what an owner derferences to, +/// for example `Box<T> -> Box<dyn Erased>`. This would be unneeded with +/// higher kinded types support in the language. +pub unsafe trait IntoErased<'a> { + /// Owner with the dereference type substituted to `Erased`. + type Erased; + /// Perform the type erasure. + fn into_erased(self) -> Self::Erased; +} + +///////////////////////////////////////////////////////////////////////////// +// OwningRef +///////////////////////////////////////////////////////////////////////////// + +impl<O, T: ?Sized> OwningRef<O, T> { + /// Creates a new owning reference from a owner + /// initialized to the direct dereference of it. + /// + /// # Example + /// ``` + /// extern crate owning_ref; + /// use owning_ref::OwningRef; + /// + /// fn main() { + /// let owning_ref = OwningRef::new(Box::new(42)); + /// assert_eq!(*owning_ref, 42); + /// } + /// ``` + pub fn new(o: O) -> Self + where O: StableAddress, + O: Deref<Target = T>, + { + OwningRef { + reference: &*o, + owner: o, + } + } + + /// Like `new`, but doesn’t require `O` to implement the `StableAddress` trait. + /// Instead, the caller is responsible to make the same promises as implementing the trait. + /// + /// This is useful for cases where coherence rules prevents implementing the trait + /// without adding a dependency to this crate in a third-party library. + pub unsafe fn new_assert_stable_address(o: O) -> Self + where O: Deref<Target = T>, + { + OwningRef { + reference: &*o, + owner: o, + } + } + + /// Converts `self` into a new owning reference that points at something reachable + /// from the previous one. + /// + /// This can be a reference to a field of `U`, something reachable from a field of + /// `U`, or even something unrelated with a `'static` lifetime. + /// + /// # Example + /// ``` + /// extern crate owning_ref; + /// use owning_ref::OwningRef; + /// + /// fn main() { + /// let owning_ref = OwningRef::new(Box::new([1, 2, 3, 4])); + /// + /// // create a owning reference that points at the + /// // third element of the array. + /// let owning_ref = owning_ref.map(|array| &array[2]); + /// assert_eq!(*owning_ref, 3); + /// } + /// ``` + pub fn map<F, U: ?Sized>(self, f: F) -> OwningRef<O, U> + where O: StableAddress, + F: FnOnce(&T) -> &U + { + OwningRef { + reference: f(&self), + owner: self.owner, + } + } + + /// Converts `self` into a new owning reference that points at something reachable + /// from the previous one or from the owner itself. + /// + /// This can be a reference to a field of `U`, something reachable from a field of + /// `U` or from the owner `O`, or even something unrelated with a `'static` lifetime. + /// + /// # Example + /// ``` + /// extern crate owning_ref; + /// use owning_ref::OwningRef; + /// + /// fn main() { + /// let owning_ref = OwningRef::new(Box::new([1, 2, 3, 4])); + /// let owning_ref = owning_ref.map(|array| &array[2]); + /// assert_eq!(*owning_ref, 3); + /// + /// // create a owning reference that points at the + /// // second element of the array from the owning ref that was pointing to the third + /// let owning_ref = owning_ref.map_with_owner(|array, _prev| &array[1]); + /// assert_eq!(*owning_ref, 2); + /// } + /// ``` + pub fn map_with_owner<F, U: ?Sized>(self, f: F) -> OwningRef<O, U> + where O: StableAddress, + F: for<'a> FnOnce(&'a O, &'a T) -> &'a U + { + OwningRef { + reference: f(&self.owner, &self), + owner: self.owner, + } + } + + /// Tries to convert `self` into a new owning reference that points + /// at something reachable from the previous one. + /// + /// This can be a reference to a field of `U`, something reachable from a field of + /// `U`, or even something unrelated with a `'static` lifetime. + /// + /// # Example + /// ``` + /// extern crate owning_ref; + /// use owning_ref::OwningRef; + /// + /// fn main() { + /// let owning_ref = OwningRef::new(Box::new([1, 2, 3, 4])); + /// + /// // create a owning reference that points at the + /// // third element of the array. + /// let owning_ref = owning_ref.try_map(|array| { + /// if array[2] == 3 { Ok(&array[2]) } else { Err(()) } + /// }); + /// assert_eq!(*owning_ref.unwrap(), 3); + /// } + /// ``` + pub fn try_map<F, U: ?Sized, E>(self, f: F) -> Result<OwningRef<O, U>, E> + where O: StableAddress, + F: FnOnce(&T) -> Result<&U, E> + { + Ok(OwningRef { + reference: f(&self)?, + owner: self.owner, + }) + } + + /// Tries to convert `self` into a new owning reference that points + /// at something reachable from the previous one. + /// + /// This can be a reference to a field of `U`, something reachable from a field of + /// `U`, or even something unrelated with a `'static` lifetime. + /// + /// # Example + /// ``` + /// extern crate owning_ref; + /// use owning_ref::OwningRef; + /// + /// fn main() { + /// let owning_ref = OwningRef::new(Box::new([1, 2, 3, 4])); + /// let owning_ref = owning_ref.map(|array| &array[2]); + /// + /// // create a owning reference that points at the + /// // second element of the array from the owning ref that was pointing to the third + /// let owning_ref = owning_ref.try_map_with_owner(|array, _prev| { + /// if array[1] == 2 { Ok(&array[1]) } else { Err(()) } + /// }); + /// assert_eq!(*owning_ref.unwrap(), 2); + /// } + /// ``` + pub fn try_map_with_owner<F, U: ?Sized, E>(self, f: F) -> Result<OwningRef<O, U>, E> + where O: StableAddress, + F: for<'a> FnOnce(&'a O, &'a T) -> Result<&'a U, E> + { + Ok(OwningRef { + reference: f(&self.owner, &self)?, + owner: self.owner, + }) + } + + /// Converts `self` into a new owning reference with a different owner type. + /// + /// The new owner type needs to still contain the original owner in some way + /// so that the reference into it remains valid. This function is marked unsafe + /// because the user needs to manually uphold this guarantee. + pub unsafe fn map_owner<F, P>(self, f: F) -> OwningRef<P, T> + where O: StableAddress, + P: StableAddress, + F: FnOnce(O) -> P + { + OwningRef { + reference: self.reference, + owner: f(self.owner), + } + } + + /// Converts `self` into a new owning reference where the owner is wrapped + /// in an additional `Box<O>`. + /// + /// This can be used to safely erase the owner of any `OwningRef<O, T>` + /// to a `OwningRef<Box<dyn Erased>, T>`. + pub fn map_owner_box(self) -> OwningRef<Box<O>, T> { + OwningRef { + reference: self.reference, + owner: Box::new(self.owner), + } + } + + /// Erases the concrete base type of the owner with a trait object. + /// + /// This allows mixing of owned references with different owner base types. + /// + /// # Example + /// ``` + /// extern crate owning_ref; + /// use owning_ref::{OwningRef, Erased}; + /// + /// fn main() { + /// // NB: Using the concrete types here for explicitnes. + /// // For less verbose code type aliases like `BoxRef` are provided. + /// + /// let owning_ref_a: OwningRef<Box<[i32; 4]>, [i32; 4]> + /// = OwningRef::new(Box::new([1, 2, 3, 4])); + /// + /// let owning_ref_b: OwningRef<Box<Vec<(i32, bool)>>, Vec<(i32, bool)>> + /// = OwningRef::new(Box::new(vec![(0, false), (1, true)])); + /// + /// let owning_ref_a: OwningRef<Box<[i32; 4]>, i32> + /// = owning_ref_a.map(|a| &a[0]); + /// + /// let owning_ref_b: OwningRef<Box<Vec<(i32, bool)>>, i32> + /// = owning_ref_b.map(|a| &a[1].0); + /// + /// let owning_refs: [OwningRef<Box<dyn Erased>, i32>; 2] + /// = [owning_ref_a.erase_owner(), owning_ref_b.erase_owner()]; + /// + /// assert_eq!(*owning_refs[0], 1); + /// assert_eq!(*owning_refs[1], 1); + /// } + /// ``` + pub fn erase_owner<'a>(self) -> OwningRef<O::Erased, T> + where O: IntoErased<'a>, + { + OwningRef { + reference: self.reference, + owner: self.owner.into_erased(), + } + } + + // TODO: wrap_owner + + /// A reference to the underlying owner. + pub fn as_owner(&self) -> &O { + &self.owner + } + + /// Discards the reference and retrieves the owner. + pub fn into_owner(self) -> O { + self.owner + } +} + +impl<O, T: ?Sized> OwningRefMut<O, T> { + /// Creates a new owning reference from a owner + /// initialized to the direct dereference of it. + /// + /// # Example + /// ``` + /// extern crate owning_ref; + /// use owning_ref::OwningRefMut; + /// + /// fn main() { + /// let owning_ref_mut = OwningRefMut::new(Box::new(42)); + /// assert_eq!(*owning_ref_mut, 42); + /// } + /// ``` + pub fn new(mut o: O) -> Self + where O: StableAddress, + O: DerefMut<Target = T>, + { + OwningRefMut { + reference: &mut *o, + owner: o, + } + } + + /// Like `new`, but doesn’t require `O` to implement the `StableAddress` trait. + /// Instead, the caller is responsible to make the same promises as implementing the trait. + /// + /// This is useful for cases where coherence rules prevents implementing the trait + /// without adding a dependency to this crate in a third-party library. + pub unsafe fn new_assert_stable_address(mut o: O) -> Self + where O: DerefMut<Target = T>, + { + OwningRefMut { + reference: &mut *o, + owner: o, + } + } + + /// Converts `self` into a new _shared_ owning reference that points at + /// something reachable from the previous one. + /// + /// This can be a reference to a field of `U`, something reachable from a field of + /// `U`, or even something unrelated with a `'static` lifetime. + /// + /// # Example + /// ``` + /// extern crate owning_ref; + /// use owning_ref::OwningRefMut; + /// + /// fn main() { + /// let owning_ref_mut = OwningRefMut::new(Box::new([1, 2, 3, 4])); + /// + /// // create a owning reference that points at the + /// // third element of the array. + /// let owning_ref = owning_ref_mut.map(|array| &array[2]); + /// assert_eq!(*owning_ref, 3); + /// } + /// ``` + pub fn map<F, U: ?Sized>(mut self, f: F) -> OwningRef<O, U> + where O: StableAddress, + F: FnOnce(&mut T) -> &U + { + OwningRef { + reference: f(&mut self), + owner: self.owner, + } + } + + /// Converts `self` into a new _mutable_ owning reference that points at + /// something reachable from the previous one. + /// + /// This can be a reference to a field of `U`, something reachable from a field of + /// `U`, or even something unrelated with a `'static` lifetime. + /// + /// # Example + /// ``` + /// extern crate owning_ref; + /// use owning_ref::OwningRefMut; + /// + /// fn main() { + /// let owning_ref_mut = OwningRefMut::new(Box::new([1, 2, 3, 4])); + /// + /// // create a owning reference that points at the + /// // third element of the array. + /// let owning_ref_mut = owning_ref_mut.map_mut(|array| &mut array[2]); + /// assert_eq!(*owning_ref_mut, 3); + /// } + /// ``` + pub fn map_mut<F, U: ?Sized>(mut self, f: F) -> OwningRefMut<O, U> + where O: StableAddress, + F: FnOnce(&mut T) -> &mut U + { + OwningRefMut { + reference: f(&mut self), + owner: self.owner, + } + } + + /// Tries to convert `self` into a new _shared_ owning reference that points + /// at something reachable from the previous one. + /// + /// This can be a reference to a field of `U`, something reachable from a field of + /// `U`, or even something unrelated with a `'static` lifetime. + /// + /// # Example + /// ``` + /// extern crate owning_ref; + /// use owning_ref::OwningRefMut; + /// + /// fn main() { + /// let owning_ref_mut = OwningRefMut::new(Box::new([1, 2, 3, 4])); + /// + /// // create a owning reference that points at the + /// // third element of the array. + /// let owning_ref = owning_ref_mut.try_map(|array| { + /// if array[2] == 3 { Ok(&array[2]) } else { Err(()) } + /// }); + /// assert_eq!(*owning_ref.unwrap(), 3); + /// } + /// ``` + pub fn try_map<F, U: ?Sized, E>(mut self, f: F) -> Result<OwningRef<O, U>, E> + where O: StableAddress, + F: FnOnce(&mut T) -> Result<&U, E> + { + Ok(OwningRef { + reference: f(&mut self)?, + owner: self.owner, + }) + } + + /// Tries to convert `self` into a new _mutable_ owning reference that points + /// at something reachable from the previous one. + /// + /// This can be a reference to a field of `U`, something reachable from a field of + /// `U`, or even something unrelated with a `'static` lifetime. + /// + /// # Example + /// ``` + /// extern crate owning_ref; + /// use owning_ref::OwningRefMut; + /// + /// fn main() { + /// let owning_ref_mut = OwningRefMut::new(Box::new([1, 2, 3, 4])); + /// + /// // create a owning reference that points at the + /// // third element of the array. + /// let owning_ref_mut = owning_ref_mut.try_map_mut(|array| { + /// if array[2] == 3 { Ok(&mut array[2]) } else { Err(()) } + /// }); + /// assert_eq!(*owning_ref_mut.unwrap(), 3); + /// } + /// ``` + pub fn try_map_mut<F, U: ?Sized, E>(mut self, f: F) -> Result<OwningRefMut<O, U>, E> + where O: StableAddress, + F: FnOnce(&mut T) -> Result<&mut U, E> + { + Ok(OwningRefMut { + reference: f(&mut self)?, + owner: self.owner, + }) + } + + /// Converts `self` into a new owning reference with a different owner type. + /// + /// The new owner type needs to still contain the original owner in some way + /// so that the reference into it remains valid. This function is marked unsafe + /// because the user needs to manually uphold this guarantee. + pub unsafe fn map_owner<F, P>(self, f: F) -> OwningRefMut<P, T> + where O: StableAddress, + P: StableAddress, + F: FnOnce(O) -> P + { + OwningRefMut { + reference: self.reference, + owner: f(self.owner), + } + } + + /// Converts `self` into a new owning reference where the owner is wrapped + /// in an additional `Box<O>`. + /// + /// This can be used to safely erase the owner of any `OwningRefMut<O, T>` + /// to a `OwningRefMut<Box<dyn Erased>, T>`. + pub fn map_owner_box(self) -> OwningRefMut<Box<O>, T> { + OwningRefMut { + reference: self.reference, + owner: Box::new(self.owner), + } + } + + /// Erases the concrete base type of the owner with a trait object. + /// + /// This allows mixing of owned references with different owner base types. + /// + /// # Example + /// ``` + /// extern crate owning_ref; + /// use owning_ref::{OwningRefMut, Erased}; + /// + /// fn main() { + /// // NB: Using the concrete types here for explicitnes. + /// // For less verbose code type aliases like `BoxRef` are provided. + /// + /// let owning_ref_mut_a: OwningRefMut<Box<[i32; 4]>, [i32; 4]> + /// = OwningRefMut::new(Box::new([1, 2, 3, 4])); + /// + /// let owning_ref_mut_b: OwningRefMut<Box<Vec<(i32, bool)>>, Vec<(i32, bool)>> + /// = OwningRefMut::new(Box::new(vec![(0, false), (1, true)])); + /// + /// let owning_ref_mut_a: OwningRefMut<Box<[i32; 4]>, i32> + /// = owning_ref_mut_a.map_mut(|a| &mut a[0]); + /// + /// let owning_ref_mut_b: OwningRefMut<Box<Vec<(i32, bool)>>, i32> + /// = owning_ref_mut_b.map_mut(|a| &mut a[1].0); + /// + /// let owning_refs_mut: [OwningRefMut<Box<dyn Erased>, i32>; 2] + /// = [owning_ref_mut_a.erase_owner(), owning_ref_mut_b.erase_owner()]; + /// + /// assert_eq!(*owning_refs_mut[0], 1); + /// assert_eq!(*owning_refs_mut[1], 1); + /// } + /// ``` + pub fn erase_owner<'a>(self) -> OwningRefMut<O::Erased, T> + where O: IntoErased<'a>, + { + OwningRefMut { + reference: self.reference, + owner: self.owner.into_erased(), + } + } + + // TODO: wrap_owner + + /// A reference to the underlying owner. + pub fn as_owner(&self) -> &O { + &self.owner + } + + /// A mutable reference to the underlying owner. + pub fn as_owner_mut(&mut self) -> &mut O { + &mut self.owner + } + + /// Discards the reference and retrieves the owner. + pub fn into_owner(self) -> O { + self.owner + } +} + +///////////////////////////////////////////////////////////////////////////// +// OwningHandle +///////////////////////////////////////////////////////////////////////////// + +use std::ops::{Deref, DerefMut}; + +/// `OwningHandle` is a complement to `OwningRef`. Where `OwningRef` allows +/// consumers to pass around an owned object and a dependent reference, +/// `OwningHandle` contains an owned object and a dependent _object_. +/// +/// `OwningHandle` can encapsulate a `RefMut` along with its associated +/// `RefCell`, or an `RwLockReadGuard` along with its associated `RwLock`. +/// However, the API is completely generic and there are no restrictions on +/// what types of owning and dependent objects may be used. +/// +/// `OwningHandle` is created by passing an owner object (which dereferences +/// to a stable address) along with a callback which receives a pointer to +/// that stable location. The callback may then dereference the pointer and +/// mint a dependent object, with the guarantee that the returned object will +/// not outlive the referent of the pointer. +/// +/// Since the callback needs to dereference a raw pointer, it requires `unsafe` +/// code. To avoid forcing this unsafety on most callers, the `ToHandle` trait is +/// implemented for common data structures. Types that implement `ToHandle` can +/// be wrapped into an `OwningHandle` without passing a callback. +pub struct OwningHandle<O, H> + where O: StableAddress, H: Deref, +{ + handle: H, + _owner: O, +} + +impl<O, H> Deref for OwningHandle<O, H> + where O: StableAddress, H: Deref, +{ + type Target = H::Target; + fn deref(&self) -> &H::Target { + self.handle.deref() + } +} + +unsafe impl<O, H> StableAddress for OwningHandle<O, H> + where O: StableAddress, H: StableAddress, +{} + +impl<O, H> DerefMut for OwningHandle<O, H> + where O: StableAddress, H: DerefMut, +{ + fn deref_mut(&mut self) -> &mut H::Target { + self.handle.deref_mut() + } +} + +/// Trait to implement the conversion of owner to handle for common types. +pub trait ToHandle { + /// The type of handle to be encapsulated by the OwningHandle. + type Handle: Deref; + + /// Given an appropriately-long-lived pointer to ourselves, create a + /// handle to be encapsulated by the `OwningHandle`. + unsafe fn to_handle(x: *const Self) -> Self::Handle; +} + +/// Trait to implement the conversion of owner to mutable handle for common types. +pub trait ToHandleMut { + /// The type of handle to be encapsulated by the OwningHandle. + type HandleMut: DerefMut; + + /// Given an appropriately-long-lived pointer to ourselves, create a + /// mutable handle to be encapsulated by the `OwningHandle`. + unsafe fn to_handle_mut(x: *const Self) -> Self::HandleMut; +} + +impl<O, H> OwningHandle<O, H> + where O: StableAddress, O::Target: ToHandle<Handle = H>, H: Deref, +{ + /// Create a new `OwningHandle` for a type that implements `ToHandle`. For types + /// that don't implement `ToHandle`, callers may invoke `new_with_fn`, which accepts + /// a callback to perform the conversion. + pub fn new(o: O) -> Self { + OwningHandle::new_with_fn(o, |x| unsafe { O::Target::to_handle(x) }) + } +} + +impl<O, H> OwningHandle<O, H> + where O: StableAddress, O::Target: ToHandleMut<HandleMut = H>, H: DerefMut, +{ + /// Create a new mutable `OwningHandle` for a type that implements `ToHandleMut`. + pub fn new_mut(o: O) -> Self { + OwningHandle::new_with_fn(o, |x| unsafe { O::Target::to_handle_mut(x) }) + } +} + +impl<O, H> OwningHandle<O, H> + where O: StableAddress, H: Deref, +{ + /// Create a new OwningHandle. The provided callback will be invoked with + /// a pointer to the object owned by `o`, and the returned value is stored + /// as the object to which this `OwningHandle` will forward `Deref` and + /// `DerefMut`. + pub fn new_with_fn<F>(o: O, f: F) -> Self + where F: FnOnce(*const O::Target) -> H + { + let h: H; + { + h = f(o.deref() as *const O::Target); + } + + OwningHandle { + handle: h, + _owner: o, + } + } + + /// Create a new OwningHandle. The provided callback will be invoked with + /// a pointer to the object owned by `o`, and the returned value is stored + /// as the object to which this `OwningHandle` will forward `Deref` and + /// `DerefMut`. + pub fn try_new<F, E>(o: O, f: F) -> Result<Self, E> + where F: FnOnce(*const O::Target) -> Result<H, E> + { + let h: H; + { + h = f(o.deref() as *const O::Target)?; + } + + Ok(OwningHandle { + handle: h, + _owner: o, + }) + } + + /// A getter for the underlying owner. + pub fn as_owner(&self) -> &O { + &self._owner + } + + /// Discards the dependent object and returns the owner. + pub fn into_owner(self) -> O { + self._owner + } +} + +///////////////////////////////////////////////////////////////////////////// +// std traits +///////////////////////////////////////////////////////////////////////////// + +use std::convert::From; +use std::fmt::{self, Debug}; +use std::marker::{Send, Sync}; +use std::cmp::{Eq, PartialEq, Ord, PartialOrd, Ordering}; +use std::hash::{Hash, Hasher}; +use std::borrow::Borrow; + +impl<O, T: ?Sized> Deref for OwningRef<O, T> { + type Target = T; + + fn deref(&self) -> &T { + unsafe { + &*self.reference + } + } +} + +impl<O, T: ?Sized> Deref for OwningRefMut<O, T> { + type Target = T; + + fn deref(&self) -> &T { + unsafe { + &*self.reference + } + } +} + +impl<O, T: ?Sized> DerefMut for OwningRefMut<O, T> { + fn deref_mut(&mut self) -> &mut T { + unsafe { + &mut *self.reference + } + } +} + +unsafe impl<O, T: ?Sized> StableAddress for OwningRef<O, T> {} + +unsafe impl<O, T: ?Sized> StableAddress for OwningRefMut<O, T> {} + +impl<O, T: ?Sized> AsRef<T> for OwningRef<O, T> { + fn as_ref(&self) -> &T { + &*self + } +} + +impl<O, T: ?Sized> AsRef<T> for OwningRefMut<O, T> { + fn as_ref(&self) -> &T { + &*self + } +} + +impl<O, T: ?Sized> AsMut<T> for OwningRefMut<O, T> { + fn as_mut(&mut self) -> &mut T { + &mut *self + } +} + +impl<O, T: ?Sized> Borrow<T> for OwningRef<O, T> { + fn borrow(&self) -> &T { + &*self + } +} + +impl<O, T: ?Sized> From<O> for OwningRef<O, T> + where O: StableAddress, + O: Deref<Target = T>, +{ + fn from(owner: O) -> Self { + OwningRef::new(owner) + } +} + +impl<O, T: ?Sized> From<O> for OwningRefMut<O, T> + where O: StableAddress, + O: DerefMut<Target = T> +{ + fn from(owner: O) -> Self { + OwningRefMut::new(owner) + } +} + +impl<O, T: ?Sized> From<OwningRefMut<O, T>> for OwningRef<O, T> + where O: StableAddress, + O: DerefMut<Target = T> +{ + fn from(other: OwningRefMut<O, T>) -> Self { + OwningRef { + owner: other.owner, + reference: other.reference, + } + } +} + +// ^ FIXME: Is a Into impl for calling into_owner() possible as well? + +impl<O, T: ?Sized> Debug for OwningRef<O, T> + where O: Debug, + T: Debug, +{ + fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> { + write!(f, + "OwningRef {{ owner: {:?}, reference: {:?} }}", + self.as_owner(), + &**self) + } +} + +impl<O, T: ?Sized> Debug for OwningRefMut<O, T> + where O: Debug, + T: Debug, +{ + fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> { + write!(f, + "OwningRefMut {{ owner: {:?}, reference: {:?} }}", + self.as_owner(), + &**self) + } +} + +impl<O, T: ?Sized> Clone for OwningRef<O, T> + where O: CloneStableAddress, +{ + fn clone(&self) -> Self { + OwningRef { + owner: self.owner.clone(), + reference: self.reference, + } + } +} + +unsafe impl<O, T: ?Sized> CloneStableAddress for OwningRef<O, T> + where O: CloneStableAddress {} + +unsafe impl<O, T: ?Sized> Send for OwningRef<O, T> + where O: Send, for<'a> (&'a T): Send {} +unsafe impl<O, T: ?Sized> Sync for OwningRef<O, T> + where O: Sync, for<'a> (&'a T): Sync {} + +unsafe impl<O, T: ?Sized> Send for OwningRefMut<O, T> + where O: Send, for<'a> (&'a mut T): Send {} +unsafe impl<O, T: ?Sized> Sync for OwningRefMut<O, T> + where O: Sync, for<'a> (&'a mut T): Sync {} + +impl Debug for dyn Erased { + fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> { + write!(f, "<dyn Erased>",) + } +} + +impl<O, T: ?Sized> PartialEq for OwningRef<O, T> where T: PartialEq { + fn eq(&self, other: &Self) -> bool { + (&*self as &T).eq(&*other as &T) + } +} + +impl<O, T: ?Sized> Eq for OwningRef<O, T> where T: Eq {} + +impl<O, T: ?Sized> PartialOrd for OwningRef<O, T> where T: PartialOrd { + fn partial_cmp(&self, other: &Self) -> Option<Ordering> { + (&*self as &T).partial_cmp(&*other as &T) + } +} + +impl<O, T: ?Sized> Ord for OwningRef<O, T> where T: Ord { + fn cmp(&self, other: &Self) -> Ordering { + (&*self as &T).cmp(&*other as &T) + } +} + +impl<O, T: ?Sized> Hash for OwningRef<O, T> where T: Hash { + fn hash<H: Hasher>(&self, state: &mut H) { + (&*self as &T).hash(state); + } +} + +impl<O, T: ?Sized> PartialEq for OwningRefMut<O, T> where T: PartialEq { + fn eq(&self, other: &Self) -> bool { + (&*self as &T).eq(&*other as &T) + } +} + +impl<O, T: ?Sized> Eq for OwningRefMut<O, T> where T: Eq {} + +impl<O, T: ?Sized> PartialOrd for OwningRefMut<O, T> where T: PartialOrd { + fn partial_cmp(&self, other: &Self) -> Option<Ordering> { + (&*self as &T).partial_cmp(&*other as &T) + } +} + +impl<O, T: ?Sized> Ord for OwningRefMut<O, T> where T: Ord { + fn cmp(&self, other: &Self) -> Ordering { + (&*self as &T).cmp(&*other as &T) + } +} + +impl<O, T: ?Sized> Hash for OwningRefMut<O, T> where T: Hash { + fn hash<H: Hasher>(&self, state: &mut H) { + (&*self as &T).hash(state); + } +} + +///////////////////////////////////////////////////////////////////////////// +// std types integration and convenience type defs +///////////////////////////////////////////////////////////////////////////// + +use std::boxed::Box; +use std::rc::Rc; +use std::sync::Arc; +use std::sync::{MutexGuard, RwLockReadGuard, RwLockWriteGuard}; +use std::cell::{Ref, RefCell, RefMut}; + +impl<T: 'static> ToHandle for RefCell<T> { + type Handle = Ref<'static, T>; + unsafe fn to_handle(x: *const Self) -> Self::Handle { (*x).borrow() } +} + +impl<T: 'static> ToHandleMut for RefCell<T> { + type HandleMut = RefMut<'static, T>; + unsafe fn to_handle_mut(x: *const Self) -> Self::HandleMut { (*x).borrow_mut() } +} + +// NB: Implementing ToHandle{,Mut} for Mutex and RwLock requires a decision +// about which handle creation to use (i.e. read() vs try_read()) as well as +// what to do with error results. + +/// Typedef of a owning reference that uses a `Box` as the owner. +pub type BoxRef<T, U = T> = OwningRef<Box<T>, U>; +/// Typedef of a owning reference that uses a `Vec` as the owner. +pub type VecRef<T, U = T> = OwningRef<Vec<T>, U>; +/// Typedef of a owning reference that uses a `String` as the owner. +pub type StringRef = OwningRef<String, str>; + +/// Typedef of a owning reference that uses a `Rc` as the owner. +pub type RcRef<T, U = T> = OwningRef<Rc<T>, U>; +/// Typedef of a owning reference that uses a `Arc` as the owner. +pub type ArcRef<T, U = T> = OwningRef<Arc<T>, U>; + +/// Typedef of a owning reference that uses a `Ref` as the owner. +pub type RefRef<'a, T, U = T> = OwningRef<Ref<'a, T>, U>; +/// Typedef of a owning reference that uses a `RefMut` as the owner. +pub type RefMutRef<'a, T, U = T> = OwningRef<RefMut<'a, T>, U>; +/// Typedef of a owning reference that uses a `MutexGuard` as the owner. +pub type MutexGuardRef<'a, T, U = T> = OwningRef<MutexGuard<'a, T>, U>; +/// Typedef of a owning reference that uses a `RwLockReadGuard` as the owner. +pub type RwLockReadGuardRef<'a, T, U = T> = OwningRef<RwLockReadGuard<'a, T>, U>; +/// Typedef of a owning reference that uses a `RwLockWriteGuard` as the owner. +pub type RwLockWriteGuardRef<'a, T, U = T> = OwningRef<RwLockWriteGuard<'a, T>, U>; + +/// Typedef of a mutable owning reference that uses a `Box` as the owner. +pub type BoxRefMut<T, U = T> = OwningRefMut<Box<T>, U>; +/// Typedef of a mutable owning reference that uses a `Vec` as the owner. +pub type VecRefMut<T, U = T> = OwningRefMut<Vec<T>, U>; +/// Typedef of a mutable owning reference that uses a `String` as the owner. +pub type StringRefMut = OwningRefMut<String, str>; + +/// Typedef of a mutable owning reference that uses a `RefMut` as the owner. +pub type RefMutRefMut<'a, T, U = T> = OwningRefMut<RefMut<'a, T>, U>; +/// Typedef of a mutable owning reference that uses a `MutexGuard` as the owner. +pub type MutexGuardRefMut<'a, T, U = T> = OwningRefMut<MutexGuard<'a, T>, U>; +/// Typedef of a mutable owning reference that uses a `RwLockWriteGuard` as the owner. +pub type RwLockWriteGuardRefMut<'a, T, U = T> = OwningRefMut<RwLockWriteGuard<'a, T>, U>; + +unsafe impl<'a, T: 'a> IntoErased<'a> for Box<T> { + type Erased = Box<dyn Erased + 'a>; + fn into_erased(self) -> Self::Erased { + self + } +} +unsafe impl<'a, T: 'a> IntoErased<'a> for Rc<T> { + type Erased = Rc<dyn Erased + 'a>; + fn into_erased(self) -> Self::Erased { + self + } +} +unsafe impl<'a, T: 'a> IntoErased<'a> for Arc<T> { + type Erased = Arc<dyn Erased + 'a>; + fn into_erased(self) -> Self::Erased { + self + } +} + +/// Typedef of a owning reference that uses an erased `Box` as the owner. +pub type ErasedBoxRef<U> = OwningRef<Box<dyn Erased>, U>; +/// Typedef of a owning reference that uses an erased `Rc` as the owner. +pub type ErasedRcRef<U> = OwningRef<Rc<dyn Erased>, U>; +/// Typedef of a owning reference that uses an erased `Arc` as the owner. +pub type ErasedArcRef<U> = OwningRef<Arc<dyn Erased>, U>; + +/// Typedef of a mutable owning reference that uses an erased `Box` as the owner. +pub type ErasedBoxRefMut<U> = OwningRefMut<Box<dyn Erased>, U>; + +#[cfg(test)] +mod tests { + mod owning_ref { + use super::super::OwningRef; + use super::super::{RcRef, BoxRef, Erased, ErasedBoxRef}; + use std::cmp::{PartialEq, Ord, PartialOrd, Ordering}; + use std::hash::{Hash, Hasher}; + use std::collections::hash_map::DefaultHasher; + use std::collections::HashMap; + use std::rc::Rc; + + #[derive(Debug, PartialEq)] + struct Example(u32, String, [u8; 3]); + fn example() -> Example { + Example(42, "hello world".to_string(), [1, 2, 3]) + } + + #[test] + fn new_deref() { + let or: OwningRef<Box<()>, ()> = OwningRef::new(Box::new(())); + assert_eq!(&*or, &()); + } + + #[test] + fn into() { + let or: OwningRef<Box<()>, ()> = Box::new(()).into(); + assert_eq!(&*or, &()); + } + + #[test] + fn map_offset_ref() { + let or: BoxRef<Example> = Box::new(example()).into(); + let or: BoxRef<_, u32> = or.map(|x| &x.0); + assert_eq!(&*or, &42); + + let or: BoxRef<Example> = Box::new(example()).into(); + let or: BoxRef<_, u8> = or.map(|x| &x.2[1]); + assert_eq!(&*or, &2); + } + + #[test] + fn map_heap_ref() { + let or: BoxRef<Example> = Box::new(example()).into(); + let or: BoxRef<_, str> = or.map(|x| &x.1[..5]); + assert_eq!(&*or, "hello"); + } + + #[test] + fn map_static_ref() { + let or: BoxRef<()> = Box::new(()).into(); + let or: BoxRef<_, str> = or.map(|_| "hello"); + assert_eq!(&*or, "hello"); + } + + #[test] + fn map_chained() { + let or: BoxRef<String> = Box::new(example().1).into(); + let or: BoxRef<_, str> = or.map(|x| &x[1..5]); + let or: BoxRef<_, str> = or.map(|x| &x[..2]); + assert_eq!(&*or, "el"); + } + + #[test] + fn map_chained_inference() { + let or = BoxRef::new(Box::new(example().1)) + .map(|x| &x[..5]) + .map(|x| &x[1..3]); + assert_eq!(&*or, "el"); + } + + #[test] + fn as_owner() { + let or: BoxRef<String> = Box::new(example().1).into(); + let or = or.map(|x| &x[..5]); + assert_eq!(&*or, "hello"); + assert_eq!(&**or.as_owner(), "hello world"); + } + + #[test] + fn into_owner() { + let or: BoxRef<String> = Box::new(example().1).into(); + let or = or.map(|x| &x[..5]); + assert_eq!(&*or, "hello"); + let s = *or.into_owner(); + assert_eq!(&s, "hello world"); + } + + #[test] + fn fmt_debug() { + let or: BoxRef<String> = Box::new(example().1).into(); + let or = or.map(|x| &x[..5]); + let s = format!("{:?}", or); + assert_eq!(&s, "OwningRef { owner: \"hello world\", reference: \"hello\" }"); + } + + #[test] + fn erased_owner() { + let o1: BoxRef<Example, str> = BoxRef::new(Box::new(example())) + .map(|x| &x.1[..]); + + let o2: BoxRef<String, str> = BoxRef::new(Box::new(example().1)) + .map(|x| &x[..]); + + let os: Vec<ErasedBoxRef<str>> = vec![o1.erase_owner(), o2.erase_owner()]; + assert!(os.iter().all(|e| &e[..] == "hello world")); + } + + #[test] + fn non_static_erased_owner() { + let foo = [413, 612]; + let bar = &foo; + + // FIXME: lifetime inference fails us, and we can't easily define a lifetime for a closure + // (see https://github.com/rust-lang/rust/issues/22340) + // So we use a function to identify the lifetimes instead. + fn borrow<'a>(a: &'a &[i32; 2]) -> &'a i32 { + &a[0] + } + + let o: BoxRef<&[i32; 2]> = Box::new(bar).into(); + let o: BoxRef<&[i32; 2], i32> = o.map(borrow); + let o: BoxRef<dyn Erased, i32> = o.erase_owner(); + + assert_eq!(*o, 413); + } + + #[test] + fn raii_locks() { + use super::super::{RefRef, RefMutRef}; + use std::cell::RefCell; + use super::super::{MutexGuardRef, RwLockReadGuardRef, RwLockWriteGuardRef}; + use std::sync::{Mutex, RwLock}; + + { + let a = RefCell::new(1); + let a = { + let a = RefRef::new(a.borrow()); + assert_eq!(*a, 1); + a + }; + assert_eq!(*a, 1); + drop(a); + } + { + let a = RefCell::new(1); + let a = { + let a = RefMutRef::new(a.borrow_mut()); + assert_eq!(*a, 1); + a + }; + assert_eq!(*a, 1); + drop(a); + } + { + let a = Mutex::new(1); + let a = { + let a = MutexGuardRef::new(a.lock().unwrap()); + assert_eq!(*a, 1); + a + }; + assert_eq!(*a, 1); + drop(a); + } + { + let a = RwLock::new(1); + let a = { + let a = RwLockReadGuardRef::new(a.read().unwrap()); + assert_eq!(*a, 1); + a + }; + assert_eq!(*a, 1); + drop(a); + } + { + let a = RwLock::new(1); + let a = { + let a = RwLockWriteGuardRef::new(a.write().unwrap()); + assert_eq!(*a, 1); + a + }; + assert_eq!(*a, 1); + drop(a); + } + } + + #[test] + fn eq() { + let or1: BoxRef<[u8]> = BoxRef::new(vec![1, 2, 3].into_boxed_slice()); + let or2: BoxRef<[u8]> = BoxRef::new(vec![1, 2, 3].into_boxed_slice()); + assert_eq!(or1.eq(&or2), true); + } + + #[test] + fn cmp() { + let or1: BoxRef<[u8]> = BoxRef::new(vec![1, 2, 3].into_boxed_slice()); + let or2: BoxRef<[u8]> = BoxRef::new(vec![4, 5, 6].into_boxed_slice()); + assert_eq!(or1.cmp(&or2), Ordering::Less); + } + + #[test] + fn partial_cmp() { + let or1: BoxRef<[u8]> = BoxRef::new(vec![4, 5, 6].into_boxed_slice()); + let or2: BoxRef<[u8]> = BoxRef::new(vec![1, 2, 3].into_boxed_slice()); + assert_eq!(or1.partial_cmp(&or2), Some(Ordering::Greater)); + } + + #[test] + fn hash() { + let mut h1 = DefaultHasher::new(); + let mut h2 = DefaultHasher::new(); + + let or1: BoxRef<[u8]> = BoxRef::new(vec![1, 2, 3].into_boxed_slice()); + let or2: BoxRef<[u8]> = BoxRef::new(vec![1, 2, 3].into_boxed_slice()); + + or1.hash(&mut h1); + or2.hash(&mut h2); + + assert_eq!(h1.finish(), h2.finish()); + } + + #[test] + fn borrow() { + let mut hash = HashMap::new(); + let key = RcRef::<String>::new(Rc::new("foo-bar".to_string())).map(|s| &s[..]); + + hash.insert(key.clone().map(|s| &s[..3]), 42); + hash.insert(key.clone().map(|s| &s[4..]), 23); + + assert_eq!(hash.get("foo"), Some(&42)); + assert_eq!(hash.get("bar"), Some(&23)); + } + + #[test] + fn total_erase() { + let a: OwningRef<Vec<u8>, [u8]> + = OwningRef::new(vec![]).map(|x| &x[..]); + let b: OwningRef<Box<[u8]>, [u8]> + = OwningRef::new(vec![].into_boxed_slice()).map(|x| &x[..]); + + let c: OwningRef<Rc<Vec<u8>>, [u8]> = unsafe {a.map_owner(Rc::new)}; + let d: OwningRef<Rc<Box<[u8]>>, [u8]> = unsafe {b.map_owner(Rc::new)}; + + let e: OwningRef<Rc<dyn Erased>, [u8]> = c.erase_owner(); + let f: OwningRef<Rc<dyn Erased>, [u8]> = d.erase_owner(); + + let _g = e.clone(); + let _h = f.clone(); + } + + #[test] + fn total_erase_box() { + let a: OwningRef<Vec<u8>, [u8]> + = OwningRef::new(vec![]).map(|x| &x[..]); + let b: OwningRef<Box<[u8]>, [u8]> + = OwningRef::new(vec![].into_boxed_slice()).map(|x| &x[..]); + + let c: OwningRef<Box<Vec<u8>>, [u8]> = a.map_owner_box(); + let d: OwningRef<Box<Box<[u8]>>, [u8]> = b.map_owner_box(); + + let _e: OwningRef<Box<dyn Erased>, [u8]> = c.erase_owner(); + let _f: OwningRef<Box<dyn Erased>, [u8]> = d.erase_owner(); + } + + #[test] + fn try_map1() { + use std::any::Any; + + let x = Box::new(123_i32); + let y: Box<dyn Any> = x; + + OwningRef::new(y).try_map(|x| x.downcast_ref::<i32>().ok_or(())).unwrap(); + } + + #[test] + fn try_map2() { + use std::any::Any; + + let x = Box::new(123_u32); + let y: Box<dyn Any> = x; + + OwningRef::new(y).try_map(|x| x.downcast_ref::<i32>().ok_or(())).unwrap_err(); + } + + #[test] + fn map_with_owner() { + let owning_ref: BoxRef<Example> = Box::new(example()).into(); + let owning_ref = owning_ref.map(|owner| &owner.1); + + owning_ref.map_with_owner(|owner, ref_field| { + assert_eq!(owner.1, *ref_field); + ref_field + }); + } + + #[test] + fn try_map_with_owner_ok() { + let owning_ref: BoxRef<Example> = Box::new(example()).into(); + let owning_ref = owning_ref.map(|owner| &owner.1); + + owning_ref.try_map_with_owner(|owner, ref_field| { + assert_eq!(owner.1, *ref_field); + Ok(ref_field) as Result<_, ()> + }).unwrap(); + } + + #[test] + fn try_map_with_owner_err() { + let owning_ref: BoxRef<Example> = Box::new(example()).into(); + let owning_ref = owning_ref.map(|owner| &owner.1); + + owning_ref.try_map_with_owner(|owner, ref_field| { + assert_eq!(owner.1, *ref_field); + Err(()) as Result<&(), _> + }).unwrap_err(); + } + } + + mod owning_handle { + use super::super::OwningHandle; + use super::super::RcRef; + use std::rc::Rc; + use std::cell::RefCell; + use std::sync::Arc; + use std::sync::RwLock; + + #[test] + fn owning_handle() { + use std::cell::RefCell; + let cell = Rc::new(RefCell::new(2)); + let cell_ref = RcRef::new(cell); + let mut handle = OwningHandle::new_with_fn(cell_ref, |x| unsafe { x.as_ref() }.unwrap().borrow_mut()); + assert_eq!(*handle, 2); + *handle = 3; + assert_eq!(*handle, 3); + } + + #[test] + fn try_owning_handle_ok() { + use std::cell::RefCell; + let cell = Rc::new(RefCell::new(2)); + let cell_ref = RcRef::new(cell); + let mut handle = OwningHandle::try_new::<_, ()>(cell_ref, |x| { + Ok(unsafe { + x.as_ref() + }.unwrap().borrow_mut()) + }).unwrap(); + assert_eq!(*handle, 2); + *handle = 3; + assert_eq!(*handle, 3); + } + + #[test] + fn try_owning_handle_err() { + use std::cell::RefCell; + let cell = Rc::new(RefCell::new(2)); + let cell_ref = RcRef::new(cell); + let handle = OwningHandle::try_new::<_, ()>(cell_ref, |x| { + if false { + return Ok(unsafe { + x.as_ref() + }.unwrap().borrow_mut()) + } + Err(()) + }); + assert!(handle.is_err()); + } + + #[test] + fn nested() { + use std::cell::RefCell; + use std::sync::{Arc, RwLock}; + + let result = { + let complex = Rc::new(RefCell::new(Arc::new(RwLock::new("someString")))); + let curr = RcRef::new(complex); + let curr = OwningHandle::new_with_fn(curr, |x| unsafe { x.as_ref() }.unwrap().borrow_mut()); + let mut curr = OwningHandle::new_with_fn(curr, |x| unsafe { x.as_ref() }.unwrap().try_write().unwrap()); + assert_eq!(*curr, "someString"); + *curr = "someOtherString"; + curr + }; + assert_eq!(*result, "someOtherString"); + } + + #[test] + fn owning_handle_safe() { + use std::cell::RefCell; + let cell = Rc::new(RefCell::new(2)); + let cell_ref = RcRef::new(cell); + let handle = OwningHandle::new(cell_ref); + assert_eq!(*handle, 2); + } + + #[test] + fn owning_handle_mut_safe() { + use std::cell::RefCell; + let cell = Rc::new(RefCell::new(2)); + let cell_ref = RcRef::new(cell); + let mut handle = OwningHandle::new_mut(cell_ref); + assert_eq!(*handle, 2); + *handle = 3; + assert_eq!(*handle, 3); + } + + #[test] + fn owning_handle_safe_2() { + let result = { + let complex = Rc::new(RefCell::new(Arc::new(RwLock::new("someString")))); + let curr = RcRef::new(complex); + let curr = OwningHandle::new_with_fn(curr, |x| unsafe { x.as_ref() }.unwrap().borrow_mut()); + let mut curr = OwningHandle::new_with_fn(curr, |x| unsafe { x.as_ref() }.unwrap().try_write().unwrap()); + assert_eq!(*curr, "someString"); + *curr = "someOtherString"; + curr + }; + assert_eq!(*result, "someOtherString"); + } + } + + mod owning_ref_mut { + use super::super::{OwningRefMut, BoxRefMut, Erased, ErasedBoxRefMut}; + use super::super::BoxRef; + use std::cmp::{PartialEq, Ord, PartialOrd, Ordering}; + use std::hash::{Hash, Hasher}; + use std::collections::hash_map::DefaultHasher; + use std::collections::HashMap; + + #[derive(Debug, PartialEq)] + struct Example(u32, String, [u8; 3]); + fn example() -> Example { + Example(42, "hello world".to_string(), [1, 2, 3]) + } + + #[test] + fn new_deref() { + let or: OwningRefMut<Box<()>, ()> = OwningRefMut::new(Box::new(())); + assert_eq!(&*or, &()); + } + + #[test] + fn new_deref_mut() { + let mut or: OwningRefMut<Box<()>, ()> = OwningRefMut::new(Box::new(())); + assert_eq!(&mut *or, &mut ()); + } + + #[test] + fn mutate() { + let mut or: OwningRefMut<Box<usize>, usize> = OwningRefMut::new(Box::new(0)); + assert_eq!(&*or, &0); + *or = 1; + assert_eq!(&*or, &1); + } + + #[test] + fn into() { + let or: OwningRefMut<Box<()>, ()> = Box::new(()).into(); + assert_eq!(&*or, &()); + } + + #[test] + fn map_offset_ref() { + let or: BoxRefMut<Example> = Box::new(example()).into(); + let or: BoxRef<_, u32> = or.map(|x| &mut x.0); + assert_eq!(&*or, &42); + + let or: BoxRefMut<Example> = Box::new(example()).into(); + let or: BoxRef<_, u8> = or.map(|x| &mut x.2[1]); + assert_eq!(&*or, &2); + } + + #[test] + fn map_heap_ref() { + let or: BoxRefMut<Example> = Box::new(example()).into(); + let or: BoxRef<_, str> = or.map(|x| &mut x.1[..5]); + assert_eq!(&*or, "hello"); + } + + #[test] + fn map_static_ref() { + let or: BoxRefMut<()> = Box::new(()).into(); + let or: BoxRef<_, str> = or.map(|_| "hello"); + assert_eq!(&*or, "hello"); + } + + #[test] + fn map_mut_offset_ref() { + let or: BoxRefMut<Example> = Box::new(example()).into(); + let or: BoxRefMut<_, u32> = or.map_mut(|x| &mut x.0); + assert_eq!(&*or, &42); + + let or: BoxRefMut<Example> = Box::new(example()).into(); + let or: BoxRefMut<_, u8> = or.map_mut(|x| &mut x.2[1]); + assert_eq!(&*or, &2); + } + + #[test] + fn map_mut_heap_ref() { + let or: BoxRefMut<Example> = Box::new(example()).into(); + let or: BoxRefMut<_, str> = or.map_mut(|x| &mut x.1[..5]); + assert_eq!(&*or, "hello"); + } + + #[test] + fn map_mut_static_ref() { + static mut MUT_S: [u8; 5] = *b"hello"; + + let mut_s: &'static mut [u8] = unsafe { &mut MUT_S }; + + let or: BoxRefMut<()> = Box::new(()).into(); + let or: BoxRefMut<_, [u8]> = or.map_mut(move |_| mut_s); + assert_eq!(&*or, b"hello"); + } + + #[test] + fn map_mut_chained() { + let or: BoxRefMut<String> = Box::new(example().1).into(); + let or: BoxRefMut<_, str> = or.map_mut(|x| &mut x[1..5]); + let or: BoxRefMut<_, str> = or.map_mut(|x| &mut x[..2]); + assert_eq!(&*or, "el"); + } + + #[test] + fn map_chained_inference() { + let or = BoxRefMut::new(Box::new(example().1)) + .map_mut(|x| &mut x[..5]) + .map_mut(|x| &mut x[1..3]); + assert_eq!(&*or, "el"); + } + + #[test] + fn try_map_mut() { + let or: BoxRefMut<String> = Box::new(example().1).into(); + let or: Result<BoxRefMut<_, str>, ()> = or.try_map_mut(|x| Ok(&mut x[1..5])); + assert_eq!(&*or.unwrap(), "ello"); + + let or: BoxRefMut<String> = Box::new(example().1).into(); + let or: Result<BoxRefMut<_, str>, ()> = or.try_map_mut(|_| Err(())); + assert!(or.is_err()); + } + + #[test] + fn as_owner() { + let or: BoxRefMut<String> = Box::new(example().1).into(); + let or = or.map_mut(|x| &mut x[..5]); + assert_eq!(&*or, "hello"); + assert_eq!(&**or.as_owner(), "hello world"); + } + + #[test] + fn into_owner() { + let or: BoxRefMut<String> = Box::new(example().1).into(); + let or = or.map_mut(|x| &mut x[..5]); + assert_eq!(&*or, "hello"); + let s = *or.into_owner(); + assert_eq!(&s, "hello world"); + } + + #[test] + fn fmt_debug() { + let or: BoxRefMut<String> = Box::new(example().1).into(); + let or = or.map_mut(|x| &mut x[..5]); + let s = format!("{:?}", or); + assert_eq!(&s, + "OwningRefMut { owner: \"hello world\", reference: \"hello\" }"); + } + + #[test] + fn erased_owner() { + let o1: BoxRefMut<Example, str> = BoxRefMut::new(Box::new(example())) + .map_mut(|x| &mut x.1[..]); + + let o2: BoxRefMut<String, str> = BoxRefMut::new(Box::new(example().1)) + .map_mut(|x| &mut x[..]); + + let os: Vec<ErasedBoxRefMut<str>> = vec![o1.erase_owner(), o2.erase_owner()]; + assert!(os.iter().all(|e| &e[..] == "hello world")); + } + + #[test] + fn non_static_erased_owner() { + let mut foo = [413, 612]; + let bar = &mut foo; + + // FIXME: lifetime inference fails us, and we can't easily define a lifetime for a closure + // (see https://github.com/rust-lang/rust/issues/22340) + // So we use a function to identify the lifetimes instead. + fn borrow<'a>(a: &'a mut &mut [i32; 2]) -> &'a mut i32 { + &mut a[0] + } + + let o: BoxRefMut<&mut [i32; 2]> = Box::new(bar).into(); + let o: BoxRefMut<&mut [i32; 2], i32> = o.map_mut(borrow); + let o: BoxRefMut<dyn Erased, i32> = o.erase_owner(); + + assert_eq!(*o, 413); + } + + #[test] + fn raii_locks() { + use super::super::RefMutRefMut; + use std::cell::RefCell; + use super::super::{MutexGuardRefMut, RwLockWriteGuardRefMut}; + use std::sync::{Mutex, RwLock}; + + { + let a = RefCell::new(1); + let a = { + let a = RefMutRefMut::new(a.borrow_mut()); + assert_eq!(*a, 1); + a + }; + assert_eq!(*a, 1); + drop(a); + } + { + let a = Mutex::new(1); + let a = { + let a = MutexGuardRefMut::new(a.lock().unwrap()); + assert_eq!(*a, 1); + a + }; + assert_eq!(*a, 1); + drop(a); + } + { + let a = RwLock::new(1); + let a = { + let a = RwLockWriteGuardRefMut::new(a.write().unwrap()); + assert_eq!(*a, 1); + a + }; + assert_eq!(*a, 1); + drop(a); + } + } + + #[test] + fn eq() { + let or1: BoxRefMut<[u8]> = BoxRefMut::new(vec![1, 2, 3].into_boxed_slice()); + let or2: BoxRefMut<[u8]> = BoxRefMut::new(vec![1, 2, 3].into_boxed_slice()); + assert_eq!(or1.eq(&or2), true); + } + + #[test] + fn cmp() { + let or1: BoxRefMut<[u8]> = BoxRefMut::new(vec![1, 2, 3].into_boxed_slice()); + let or2: BoxRefMut<[u8]> = BoxRefMut::new(vec![4, 5, 6].into_boxed_slice()); + assert_eq!(or1.cmp(&or2), Ordering::Less); + } + + #[test] + fn partial_cmp() { + let or1: BoxRefMut<[u8]> = BoxRefMut::new(vec![4, 5, 6].into_boxed_slice()); + let or2: BoxRefMut<[u8]> = BoxRefMut::new(vec![1, 2, 3].into_boxed_slice()); + assert_eq!(or1.partial_cmp(&or2), Some(Ordering::Greater)); + } + + #[test] + fn hash() { + let mut h1 = DefaultHasher::new(); + let mut h2 = DefaultHasher::new(); + + let or1: BoxRefMut<[u8]> = BoxRefMut::new(vec![1, 2, 3].into_boxed_slice()); + let or2: BoxRefMut<[u8]> = BoxRefMut::new(vec![1, 2, 3].into_boxed_slice()); + + or1.hash(&mut h1); + or2.hash(&mut h2); + + assert_eq!(h1.finish(), h2.finish()); + } + + #[test] + fn borrow() { + let mut hash = HashMap::new(); + let key1 = BoxRefMut::<String>::new(Box::new("foo".to_string())).map(|s| &s[..]); + let key2 = BoxRefMut::<String>::new(Box::new("bar".to_string())).map(|s| &s[..]); + + hash.insert(key1, 42); + hash.insert(key2, 23); + + assert_eq!(hash.get("foo"), Some(&42)); + assert_eq!(hash.get("bar"), Some(&23)); + } + + #[test] + fn total_erase() { + let a: OwningRefMut<Vec<u8>, [u8]> + = OwningRefMut::new(vec![]).map_mut(|x| &mut x[..]); + let b: OwningRefMut<Box<[u8]>, [u8]> + = OwningRefMut::new(vec![].into_boxed_slice()).map_mut(|x| &mut x[..]); + + let c: OwningRefMut<Box<Vec<u8>>, [u8]> = unsafe {a.map_owner(Box::new)}; + let d: OwningRefMut<Box<Box<[u8]>>, [u8]> = unsafe {b.map_owner(Box::new)}; + + let _e: OwningRefMut<Box<dyn Erased>, [u8]> = c.erase_owner(); + let _f: OwningRefMut<Box<dyn Erased>, [u8]> = d.erase_owner(); + } + + #[test] + fn total_erase_box() { + let a: OwningRefMut<Vec<u8>, [u8]> + = OwningRefMut::new(vec![]).map_mut(|x| &mut x[..]); + let b: OwningRefMut<Box<[u8]>, [u8]> + = OwningRefMut::new(vec![].into_boxed_slice()).map_mut(|x| &mut x[..]); + + let c: OwningRefMut<Box<Vec<u8>>, [u8]> = a.map_owner_box(); + let d: OwningRefMut<Box<Box<[u8]>>, [u8]> = b.map_owner_box(); + + let _e: OwningRefMut<Box<dyn Erased>, [u8]> = c.erase_owner(); + let _f: OwningRefMut<Box<dyn Erased>, [u8]> = d.erase_owner(); + } + + #[test] + fn try_map1() { + use std::any::Any; + + let x = Box::new(123_i32); + let y: Box<dyn Any> = x; + + OwningRefMut::new(y).try_map_mut(|x| x.downcast_mut::<i32>().ok_or(())).unwrap(); + } + + #[test] + fn try_map2() { + use std::any::Any; + + let x = Box::new(123_u32); + let y: Box<dyn Any> = x; + + OwningRefMut::new(y).try_map_mut(|x| x.downcast_mut::<i32>().ok_or(())).unwrap_err(); + } + + #[test] + fn try_map3() { + use std::any::Any; + + let x = Box::new(123_i32); + let y: Box<dyn Any> = x; + + OwningRefMut::new(y).try_map(|x| x.downcast_ref::<i32>().ok_or(())).unwrap(); + } + + #[test] + fn try_map4() { + use std::any::Any; + + let x = Box::new(123_u32); + let y: Box<dyn Any> = x; + + OwningRefMut::new(y).try_map(|x| x.downcast_ref::<i32>().ok_or(())).unwrap_err(); + } + + #[test] + fn into_owning_ref() { + use super::super::BoxRef; + + let or: BoxRefMut<()> = Box::new(()).into(); + let or: BoxRef<()> = or.into(); + assert_eq!(&*or, &()); + } + + struct Foo { + u: u32, + } + struct Bar { + f: Foo, + } + + #[test] + fn ref_mut() { + use std::cell::RefCell; + + let a = RefCell::new(Bar { f: Foo { u: 42 } }); + let mut b = OwningRefMut::new(a.borrow_mut()); + assert_eq!(b.f.u, 42); + b.f.u = 43; + let mut c = b.map_mut(|x| &mut x.f); + assert_eq!(c.u, 43); + c.u = 44; + let mut d = c.map_mut(|x| &mut x.u); + assert_eq!(*d, 44); + *d = 45; + assert_eq!(*d, 45); + } + } +} |