diff options
Diffstat (limited to 'library/core/src/hash/mod.rs')
| -rw-r--r-- | library/core/src/hash/mod.rs | 83 |
1 files changed, 56 insertions, 27 deletions
diff --git a/library/core/src/hash/mod.rs b/library/core/src/hash/mod.rs index aa13435e6..c755afa39 100644 --- a/library/core/src/hash/mod.rs +++ b/library/core/src/hash/mod.rs @@ -86,7 +86,8 @@ #![stable(feature = "rust1", since = "1.0.0")] use crate::fmt; -use crate::marker; +use crate::intrinsics::const_eval_select; +use crate::marker::{self, Destruct}; #[stable(feature = "rust1", since = "1.0.0")] #[allow(deprecated)] @@ -183,6 +184,7 @@ mod sip; /// [impl]: ../../std/primitive.str.html#impl-Hash-for-str #[stable(feature = "rust1", since = "1.0.0")] #[rustc_diagnostic_item = "Hash"] +#[const_trait] pub trait Hash { /// Feeds this value into the given [`Hasher`]. /// @@ -234,13 +236,25 @@ pub trait Hash { /// [`hash`]: Hash::hash /// [`hash_slice`]: Hash::hash_slice #[stable(feature = "hash_slice", since = "1.3.0")] - fn hash_slice<H: Hasher>(data: &[Self], state: &mut H) + fn hash_slice<H: ~const Hasher>(data: &[Self], state: &mut H) where Self: Sized, { - for piece in data { - piece.hash(state); + //FIXME(const_trait_impl): revert to only a for loop + fn rt<T: Hash, H: Hasher>(data: &[T], state: &mut H) { + for piece in data { + piece.hash(state) + } + } + const fn ct<T: ~const Hash, H: ~const Hasher>(data: &[T], state: &mut H) { + let mut i = 0; + while i < data.len() { + data[i].hash(state); + i += 1; + } } + // SAFETY: same behavior, CT just uses while instead of for + unsafe { const_eval_select((data, state), ct, rt) }; } } @@ -313,6 +327,7 @@ pub use macros::Hash; /// [`write_u8`]: Hasher::write_u8 /// [`write_u32`]: Hasher::write_u32 #[stable(feature = "rust1", since = "1.0.0")] +#[const_trait] pub trait Hasher { /// Returns the hash value for the values written so far. /// @@ -558,7 +573,8 @@ pub trait Hasher { } #[stable(feature = "indirect_hasher_impl", since = "1.22.0")] -impl<H: Hasher + ?Sized> Hasher for &mut H { +#[rustc_const_unstable(feature = "const_hash", issue = "104061")] +impl<H: ~const Hasher + ?Sized> const Hasher for &mut H { fn finish(&self) -> u64 { (**self).finish() } @@ -638,6 +654,7 @@ impl<H: Hasher + ?Sized> Hasher for &mut H { /// [`build_hasher`]: BuildHasher::build_hasher /// [`HashMap`]: ../../std/collections/struct.HashMap.html #[stable(since = "1.7.0", feature = "build_hasher")] +#[const_trait] pub trait BuildHasher { /// Type of the hasher that will be created. #[stable(since = "1.7.0", feature = "build_hasher")] @@ -698,9 +715,10 @@ pub trait BuildHasher { /// ); /// ``` #[unstable(feature = "build_hasher_simple_hash_one", issue = "86161")] - fn hash_one<T: Hash>(&self, x: T) -> u64 + fn hash_one<T: ~const Hash + ~const Destruct>(&self, x: T) -> u64 where Self: Sized, + Self::Hasher: ~const Hasher + ~const Destruct, { let mut hasher = self.build_hasher(); x.hash(&mut hasher); @@ -764,7 +782,8 @@ impl<H> fmt::Debug for BuildHasherDefault<H> { } #[stable(since = "1.7.0", feature = "build_hasher")] -impl<H: Default + Hasher> BuildHasher for BuildHasherDefault<H> { +#[rustc_const_unstable(feature = "const_hash", issue = "104061")] +impl<H: ~const Default + Hasher> const BuildHasher for BuildHasherDefault<H> { type Hasher = H; fn build_hasher(&self) -> H { @@ -806,14 +825,15 @@ mod impls { macro_rules! impl_write { ($(($ty:ident, $meth:ident),)*) => {$( #[stable(feature = "rust1", since = "1.0.0")] - impl Hash for $ty { + #[rustc_const_unstable(feature = "const_hash", issue = "104061")] + impl const Hash for $ty { #[inline] - fn hash<H: Hasher>(&self, state: &mut H) { + fn hash<H: ~const Hasher>(&self, state: &mut H) { state.$meth(*self) } #[inline] - fn hash_slice<H: Hasher>(data: &[$ty], state: &mut H) { + fn hash_slice<H: ~const Hasher>(data: &[$ty], state: &mut H) { let newlen = data.len() * mem::size_of::<$ty>(); let ptr = data.as_ptr() as *const u8; // SAFETY: `ptr` is valid and aligned, as this macro is only used @@ -842,33 +862,37 @@ mod impls { } #[stable(feature = "rust1", since = "1.0.0")] - impl Hash for bool { + #[rustc_const_unstable(feature = "const_hash", issue = "104061")] + impl const Hash for bool { #[inline] - fn hash<H: Hasher>(&self, state: &mut H) { + fn hash<H: ~const Hasher>(&self, state: &mut H) { state.write_u8(*self as u8) } } #[stable(feature = "rust1", since = "1.0.0")] - impl Hash for char { + #[rustc_const_unstable(feature = "const_hash", issue = "104061")] + impl const Hash for char { #[inline] - fn hash<H: Hasher>(&self, state: &mut H) { + fn hash<H: ~const Hasher>(&self, state: &mut H) { state.write_u32(*self as u32) } } #[stable(feature = "rust1", since = "1.0.0")] - impl Hash for str { + #[rustc_const_unstable(feature = "const_hash", issue = "104061")] + impl const Hash for str { #[inline] - fn hash<H: Hasher>(&self, state: &mut H) { + fn hash<H: ~const Hasher>(&self, state: &mut H) { state.write_str(self); } } #[stable(feature = "never_hash", since = "1.29.0")] - impl Hash for ! { + #[rustc_const_unstable(feature = "const_hash", issue = "104061")] + impl const Hash for ! { #[inline] - fn hash<H: Hasher>(&self, _: &mut H) { + fn hash<H: ~const Hasher>(&self, _: &mut H) { *self } } @@ -876,9 +900,10 @@ mod impls { macro_rules! impl_hash_tuple { () => ( #[stable(feature = "rust1", since = "1.0.0")] - impl Hash for () { + #[rustc_const_unstable(feature = "const_hash", issue = "104061")] + impl const Hash for () { #[inline] - fn hash<H: Hasher>(&self, _state: &mut H) {} + fn hash<H: ~const Hasher>(&self, _state: &mut H) {} } ); @@ -886,10 +911,11 @@ mod impls { maybe_tuple_doc! { $($name)+ @ #[stable(feature = "rust1", since = "1.0.0")] - impl<$($name: Hash),+> Hash for ($($name,)+) where last_type!($($name,)+): ?Sized { + #[rustc_const_unstable(feature = "const_hash", issue = "104061")] + impl<$($name: ~const Hash),+> const Hash for ($($name,)+) where last_type!($($name,)+): ?Sized { #[allow(non_snake_case)] #[inline] - fn hash<S: Hasher>(&self, state: &mut S) { + fn hash<S: ~const Hasher>(&self, state: &mut S) { let ($(ref $name,)+) = *self; $($name.hash(state);)+ } @@ -932,24 +958,27 @@ mod impls { impl_hash_tuple! { T B C D E F G H I J K L } #[stable(feature = "rust1", since = "1.0.0")] - impl<T: Hash> Hash for [T] { + #[rustc_const_unstable(feature = "const_hash", issue = "104061")] + impl<T: ~const Hash> const Hash for [T] { #[inline] - fn hash<H: Hasher>(&self, state: &mut H) { + fn hash<H: ~const Hasher>(&self, state: &mut H) { state.write_length_prefix(self.len()); Hash::hash_slice(self, state) } } #[stable(feature = "rust1", since = "1.0.0")] - impl<T: ?Sized + Hash> Hash for &T { + #[rustc_const_unstable(feature = "const_hash", issue = "104061")] + impl<T: ?Sized + ~const Hash> const Hash for &T { #[inline] - fn hash<H: Hasher>(&self, state: &mut H) { + fn hash<H: ~const Hasher>(&self, state: &mut H) { (**self).hash(state); } } #[stable(feature = "rust1", since = "1.0.0")] - impl<T: ?Sized + Hash> Hash for &mut T { + #[rustc_const_unstable(feature = "const_hash", issue = "104061")] + impl<T: ?Sized + ~const Hash> const Hash for &mut T { #[inline] fn hash<H: Hasher>(&self, state: &mut H) { (**self).hash(state); |