| use crate::convert::TryInto; |
| use crate::num::{NonZeroI128, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI8, NonZeroIsize}; |
| use crate::num::{NonZeroU128, NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU8, NonZeroUsize}; |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<A, B, const N: usize> PartialEq<[B; N]> for [A; N] |
| where |
| A: PartialEq<B>, |
| { |
| #[inline] |
| fn eq(&self, other: &[B; N]) -> bool { |
| SpecArrayEq::spec_eq(self, other) |
| } |
| #[inline] |
| fn ne(&self, other: &[B; N]) -> bool { |
| SpecArrayEq::spec_ne(self, other) |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<A, B, const N: usize> PartialEq<[B]> for [A; N] |
| where |
| A: PartialEq<B>, |
| { |
| #[inline] |
| fn eq(&self, other: &[B]) -> bool { |
| let b: Result<&[B; N], _> = other.try_into(); |
| match b { |
| Ok(b) => *self == *b, |
| Err(_) => false, |
| } |
| } |
| #[inline] |
| fn ne(&self, other: &[B]) -> bool { |
| let b: Result<&[B; N], _> = other.try_into(); |
| match b { |
| Ok(b) => *self != *b, |
| Err(_) => true, |
| } |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<A, B, const N: usize> PartialEq<[A; N]> for [B] |
| where |
| B: PartialEq<A>, |
| { |
| #[inline] |
| fn eq(&self, other: &[A; N]) -> bool { |
| let b: Result<&[B; N], _> = self.try_into(); |
| match b { |
| Ok(b) => *b == *other, |
| Err(_) => false, |
| } |
| } |
| #[inline] |
| fn ne(&self, other: &[A; N]) -> bool { |
| let b: Result<&[B; N], _> = self.try_into(); |
| match b { |
| Ok(b) => *b != *other, |
| Err(_) => true, |
| } |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<A, B, const N: usize> PartialEq<&[B]> for [A; N] |
| where |
| A: PartialEq<B>, |
| { |
| #[inline] |
| fn eq(&self, other: &&[B]) -> bool { |
| *self == **other |
| } |
| #[inline] |
| fn ne(&self, other: &&[B]) -> bool { |
| *self != **other |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<A, B, const N: usize> PartialEq<[A; N]> for &[B] |
| where |
| B: PartialEq<A>, |
| { |
| #[inline] |
| fn eq(&self, other: &[A; N]) -> bool { |
| **self == *other |
| } |
| #[inline] |
| fn ne(&self, other: &[A; N]) -> bool { |
| **self != *other |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<A, B, const N: usize> PartialEq<&mut [B]> for [A; N] |
| where |
| A: PartialEq<B>, |
| { |
| #[inline] |
| fn eq(&self, other: &&mut [B]) -> bool { |
| *self == **other |
| } |
| #[inline] |
| fn ne(&self, other: &&mut [B]) -> bool { |
| *self != **other |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<A, B, const N: usize> PartialEq<[A; N]> for &mut [B] |
| where |
| B: PartialEq<A>, |
| { |
| #[inline] |
| fn eq(&self, other: &[A; N]) -> bool { |
| **self == *other |
| } |
| #[inline] |
| fn ne(&self, other: &[A; N]) -> bool { |
| **self != *other |
| } |
| } |
| |
| // NOTE: some less important impls are omitted to reduce code bloat |
| // __impl_slice_eq2! { [A; $N], &'b [B; $N] } |
| // __impl_slice_eq2! { [A; $N], &'b mut [B; $N] } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T: Eq, const N: usize> Eq for [T; N] {} |
| |
| trait SpecArrayEq<Other, const N: usize>: Sized { |
| fn spec_eq(a: &[Self; N], b: &[Other; N]) -> bool; |
| fn spec_ne(a: &[Self; N], b: &[Other; N]) -> bool; |
| } |
| |
| impl<T: PartialEq<Other>, Other, const N: usize> SpecArrayEq<Other, N> for T { |
| default fn spec_eq(a: &[Self; N], b: &[Other; N]) -> bool { |
| a[..] == b[..] |
| } |
| default fn spec_ne(a: &[Self; N], b: &[Other; N]) -> bool { |
| a[..] != b[..] |
| } |
| } |
| |
| impl<T: IsRawEqComparable<U>, U, const N: usize> SpecArrayEq<U, N> for T { |
| fn spec_eq(a: &[T; N], b: &[U; N]) -> bool { |
| // SAFETY: This is why `IsRawEqComparable` is an `unsafe trait`. |
| unsafe { |
| let b = &*b.as_ptr().cast::<[T; N]>(); |
| crate::intrinsics::raw_eq(a, b) |
| } |
| } |
| fn spec_ne(a: &[T; N], b: &[U; N]) -> bool { |
| !Self::spec_eq(a, b) |
| } |
| } |
| |
| /// `U` exists on here mostly because `min_specialization` didn't let me |
| /// repeat the `T` type parameter in the above specialization, so instead |
| /// the `T == U` constraint comes from the impls on this. |
| /// # Safety |
| /// - Neither `Self` nor `U` has any padding. |
| /// - `Self` and `U` have the same layout. |
| /// - `Self: PartialEq<U>` is byte-wise (this means no floats, among other things) |
| #[rustc_specialization_trait] |
| unsafe trait IsRawEqComparable<U>: PartialEq<U> {} |
| |
| macro_rules! is_raw_eq_comparable { |
| ($($t:ty),+ $(,)?) => {$( |
| unsafe impl IsRawEqComparable<$t> for $t {} |
| )+}; |
| } |
| |
| // 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* (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 and no pointers, |
| // and they compare like their underlying numeric type. |
| is_raw_eq_comparable!( |
| NonZeroU8, |
| NonZeroU16, |
| NonZeroU32, |
| NonZeroU64, |
| NonZeroU128, |
| NonZeroUsize, |
| NonZeroI8, |
| NonZeroI16, |
| NonZeroI32, |
| NonZeroI64, |
| NonZeroI128, |
| NonZeroIsize, |
| ); |
| |
| // SAFETY: The NonZero types have the "null" optimization guaranteed, and thus |
| // are also safe to equality-compare bitwise inside an `Option`. |
| // The way `PartialOrd` is defined for `Option` means that this wouldn't work |
| // for `<` or `>` on the signed types, but since we only do `==` it's fine. |
| is_raw_eq_comparable!( |
| Option<NonZeroU8>, |
| Option<NonZeroU16>, |
| Option<NonZeroU32>, |
| Option<NonZeroU64>, |
| Option<NonZeroU128>, |
| Option<NonZeroUsize>, |
| Option<NonZeroI8>, |
| Option<NonZeroI16>, |
| Option<NonZeroI32>, |
| Option<NonZeroI64>, |
| Option<NonZeroI128>, |
| Option<NonZeroIsize>, |
| ); |