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Diffstat (limited to 'vendor/bytemuck/src/zeroable.rs')
-rw-r--r-- | vendor/bytemuck/src/zeroable.rs | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/vendor/bytemuck/src/zeroable.rs b/vendor/bytemuck/src/zeroable.rs new file mode 100644 index 0000000..b64a9bf --- /dev/null +++ b/vendor/bytemuck/src/zeroable.rs @@ -0,0 +1,245 @@ +use super::*; + +/// Trait for types that can be safely created with +/// [`zeroed`](core::mem::zeroed). +/// +/// An all-zeroes value may or may not be the same value as the +/// [Default](core::default::Default) value of the type. +/// +/// ## Safety +/// +/// * Your type must be inhabited (eg: no +/// [Infallible](core::convert::Infallible)). +/// * Your type must be allowed to be an "all zeroes" bit pattern (eg: no +/// [`NonNull<T>`](core::ptr::NonNull)). +/// +/// ## Features +/// +/// Some `impl`s are feature gated due to the MSRV policy: +/// +/// * `MaybeUninit<T>` was not available in 1.34.0, but is available under the +/// `zeroable_maybe_uninit` feature flag. +/// * `Atomic*` types require Rust 1.60.0 or later to work on certain platforms, +/// but is available under the `zeroable_atomics` feature flag. +/// * `[T; N]` for arbitrary `N` requires the `min_const_generics` feature flag. +pub unsafe trait Zeroable: Sized { + /// Calls [`zeroed`](core::mem::zeroed). + /// + /// This is a trait method so that you can write `MyType::zeroed()` in your + /// code. It is a contract of this trait that if you implement it on your type + /// you **must not** override this method. + #[inline] + fn zeroed() -> Self { + unsafe { core::mem::zeroed() } + } +} +unsafe impl Zeroable for () {} +unsafe impl Zeroable for bool {} +unsafe impl Zeroable for char {} +unsafe impl Zeroable for u8 {} +unsafe impl Zeroable for i8 {} +unsafe impl Zeroable for u16 {} +unsafe impl Zeroable for i16 {} +unsafe impl Zeroable for u32 {} +unsafe impl Zeroable for i32 {} +unsafe impl Zeroable for u64 {} +unsafe impl Zeroable for i64 {} +unsafe impl Zeroable for usize {} +unsafe impl Zeroable for isize {} +unsafe impl Zeroable for u128 {} +unsafe impl Zeroable for i128 {} +unsafe impl Zeroable for f32 {} +unsafe impl Zeroable for f64 {} +unsafe impl<T: Zeroable> Zeroable for Wrapping<T> {} +unsafe impl<T: Zeroable> Zeroable for core::cmp::Reverse<T> {} + +// Note: we can't implement this for all `T: ?Sized` types because it would +// create NULL pointers for vtables. +// Maybe one day this could be changed to be implemented for +// `T: ?Sized where <T as core::ptr::Pointee>::Metadata: Zeroable`. +unsafe impl<T> Zeroable for *mut T {} +unsafe impl<T> Zeroable for *const T {} +unsafe impl<T> Zeroable for *mut [T] {} +unsafe impl<T> Zeroable for *const [T] {} +unsafe impl Zeroable for *mut str {} +unsafe impl Zeroable for *const str {} + +unsafe impl<T: ?Sized> Zeroable for PhantomData<T> {} +unsafe impl Zeroable for PhantomPinned {} +unsafe impl<T: Zeroable> Zeroable for ManuallyDrop<T> {} +unsafe impl<T: Zeroable> Zeroable for core::cell::UnsafeCell<T> {} +unsafe impl<T: Zeroable> Zeroable for core::cell::Cell<T> {} + +#[cfg(feature = "zeroable_atomics")] +#[cfg_attr(feature = "nightly_docs", doc(cfg(feature = "zeroable_atomics")))] +mod atomic_impls { + use super::Zeroable; + + #[cfg(target_has_atomic = "8")] + unsafe impl Zeroable for core::sync::atomic::AtomicBool {} + #[cfg(target_has_atomic = "8")] + unsafe impl Zeroable for core::sync::atomic::AtomicU8 {} + #[cfg(target_has_atomic = "8")] + unsafe impl Zeroable for core::sync::atomic::AtomicI8 {} + + #[cfg(target_has_atomic = "16")] + unsafe impl Zeroable for core::sync::atomic::AtomicU16 {} + #[cfg(target_has_atomic = "16")] + unsafe impl Zeroable for core::sync::atomic::AtomicI16 {} + + #[cfg(target_has_atomic = "32")] + unsafe impl Zeroable for core::sync::atomic::AtomicU32 {} + #[cfg(target_has_atomic = "32")] + unsafe impl Zeroable for core::sync::atomic::AtomicI32 {} + + #[cfg(target_has_atomic = "64")] + unsafe impl Zeroable for core::sync::atomic::AtomicU64 {} + #[cfg(target_has_atomic = "64")] + unsafe impl Zeroable for core::sync::atomic::AtomicI64 {} + + #[cfg(target_has_atomic = "ptr")] + unsafe impl Zeroable for core::sync::atomic::AtomicUsize {} + #[cfg(target_has_atomic = "ptr")] + unsafe impl Zeroable for core::sync::atomic::AtomicIsize {} + + #[cfg(target_has_atomic = "ptr")] + unsafe impl<T> Zeroable for core::sync::atomic::AtomicPtr<T> {} +} + +#[cfg(feature = "zeroable_maybe_uninit")] +#[cfg_attr( + feature = "nightly_docs", + doc(cfg(feature = "zeroable_maybe_uninit")) +)] +unsafe impl<T> Zeroable for core::mem::MaybeUninit<T> {} + +unsafe impl<A: Zeroable> Zeroable for (A,) {} +unsafe impl<A: Zeroable, B: Zeroable> Zeroable for (A, B) {} +unsafe impl<A: Zeroable, B: Zeroable, C: Zeroable> Zeroable for (A, B, C) {} +unsafe impl<A: Zeroable, B: Zeroable, C: Zeroable, D: Zeroable> Zeroable + for (A, B, C, D) +{ +} +unsafe impl<A: Zeroable, B: Zeroable, C: Zeroable, D: Zeroable, E: Zeroable> + Zeroable for (A, B, C, D, E) +{ +} +unsafe impl< + A: Zeroable, + B: Zeroable, + C: Zeroable, + D: Zeroable, + E: Zeroable, + F: Zeroable, + > Zeroable for (A, B, C, D, E, F) +{ +} +unsafe impl< + A: Zeroable, + B: Zeroable, + C: Zeroable, + D: Zeroable, + E: Zeroable, + F: Zeroable, + G: Zeroable, + > Zeroable for (A, B, C, D, E, F, G) +{ +} +unsafe impl< + A: Zeroable, + B: Zeroable, + C: Zeroable, + D: Zeroable, + E: Zeroable, + F: Zeroable, + G: Zeroable, + H: Zeroable, + > Zeroable for (A, B, C, D, E, F, G, H) +{ +} + +#[cfg(feature = "min_const_generics")] +#[cfg_attr(feature = "nightly_docs", doc(cfg(feature = "min_const_generics")))] +unsafe impl<T, const N: usize> Zeroable for [T; N] where T: Zeroable {} + +#[cfg(not(feature = "min_const_generics"))] +impl_unsafe_marker_for_array!( + Zeroable, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, + 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 48, 64, 96, 128, 256, + 512, 1024, 2048, 4096 +); + +impl_unsafe_marker_for_simd!( + #[cfg(all(target_arch = "wasm32", feature = "wasm_simd"))] + unsafe impl Zeroable for wasm32::{v128} +); + +impl_unsafe_marker_for_simd!( + #[cfg(all(target_arch = "aarch64", feature = "aarch64_simd"))] + unsafe impl Zeroable for aarch64::{ + float32x2_t, float32x2x2_t, float32x2x3_t, float32x2x4_t, float32x4_t, + float32x4x2_t, float32x4x3_t, float32x4x4_t, float64x1_t, float64x1x2_t, + float64x1x3_t, float64x1x4_t, float64x2_t, float64x2x2_t, float64x2x3_t, + float64x2x4_t, int16x4_t, int16x4x2_t, int16x4x3_t, int16x4x4_t, int16x8_t, + int16x8x2_t, int16x8x3_t, int16x8x4_t, int32x2_t, int32x2x2_t, int32x2x3_t, + int32x2x4_t, int32x4_t, int32x4x2_t, int32x4x3_t, int32x4x4_t, int64x1_t, + int64x1x2_t, int64x1x3_t, int64x1x4_t, int64x2_t, int64x2x2_t, int64x2x3_t, + int64x2x4_t, int8x16_t, int8x16x2_t, int8x16x3_t, int8x16x4_t, int8x8_t, + int8x8x2_t, int8x8x3_t, int8x8x4_t, poly16x4_t, poly16x4x2_t, poly16x4x3_t, + poly16x4x4_t, poly16x8_t, poly16x8x2_t, poly16x8x3_t, poly16x8x4_t, + poly64x1_t, poly64x1x2_t, poly64x1x3_t, poly64x1x4_t, poly64x2_t, + poly64x2x2_t, poly64x2x3_t, poly64x2x4_t, poly8x16_t, poly8x16x2_t, + poly8x16x3_t, poly8x16x4_t, poly8x8_t, poly8x8x2_t, poly8x8x3_t, poly8x8x4_t, + uint16x4_t, uint16x4x2_t, uint16x4x3_t, uint16x4x4_t, uint16x8_t, + uint16x8x2_t, uint16x8x3_t, uint16x8x4_t, uint32x2_t, uint32x2x2_t, + uint32x2x3_t, uint32x2x4_t, uint32x4_t, uint32x4x2_t, uint32x4x3_t, + uint32x4x4_t, uint64x1_t, uint64x1x2_t, uint64x1x3_t, uint64x1x4_t, + uint64x2_t, uint64x2x2_t, uint64x2x3_t, uint64x2x4_t, uint8x16_t, + uint8x16x2_t, uint8x16x3_t, uint8x16x4_t, uint8x8_t, uint8x8x2_t, + uint8x8x3_t, uint8x8x4_t, + } +); + +impl_unsafe_marker_for_simd!( + #[cfg(target_arch = "x86")] + unsafe impl Zeroable for x86::{ + __m128i, __m128, __m128d, + __m256i, __m256, __m256d, + } +); + +impl_unsafe_marker_for_simd!( + #[cfg(target_arch = "x86_64")] + unsafe impl Zeroable for x86_64::{ + __m128i, __m128, __m128d, + __m256i, __m256, __m256d, + } +); + +#[cfg(feature = "nightly_portable_simd")] +#[cfg_attr( + feature = "nightly_docs", + doc(cfg(feature = "nightly_portable_simd")) +)] +unsafe impl<T, const N: usize> Zeroable for core::simd::Simd<T, N> +where + T: core::simd::SimdElement + Zeroable, + core::simd::LaneCount<N>: core::simd::SupportedLaneCount, +{ +} + +impl_unsafe_marker_for_simd!( + #[cfg(all(target_arch = "x86", feature = "nightly_stdsimd"))] + unsafe impl Zeroable for x86::{ + __m128bh, __m256bh, __m512, + __m512bh, __m512d, __m512i, + } +); + +impl_unsafe_marker_for_simd!( + #[cfg(all(target_arch = "x86_64", feature = "nightly_stdsimd"))] + unsafe impl Zeroable for x86_64::{ + __m128bh, __m256bh, __m512, + __m512bh, __m512d, __m512i, + } +); 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