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Add array_stage0.rs for bootstrapping.
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‎src/libcore/array_stage0.rs

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//! Implementations of things like `Eq` for fixed-length arrays
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//! up to a certain length. Eventually we should able to generalize
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//! to all lengths.
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//!
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//! *[See also the array primitive type](../../std/primitive.array.html).*
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#![stable(feature = "core_array", since = "1.36.0")]
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use crate::borrow::{Borrow, BorrowMut};
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use crate::cmp::Ordering;
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use crate::convert::{Infallible, TryFrom};
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use crate::fmt;
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use crate::hash::{Hash, self};
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use crate::marker::Unsize;
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use crate::slice::{Iter, IterMut};
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/// Utility trait implemented only on arrays of fixed size
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///
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/// This trait can be used to implement other traits on fixed-size arrays
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/// without causing much metadata bloat.
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///
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/// The trait is marked unsafe in order to restrict implementors to fixed-size
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/// arrays. User of this trait can assume that implementors have the exact
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/// layout in memory of a fixed size array (for example, for unsafe
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/// initialization).
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///
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/// Note that the traits AsRef and AsMut provide similar methods for types that
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/// may not be fixed-size arrays. Implementors should prefer those traits
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/// instead.
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#[unstable(feature = "fixed_size_array", issue = "27778")]
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pub unsafe trait FixedSizeArray<T> {
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/// Converts the array to immutable slice
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#[unstable(feature = "fixed_size_array", issue = "27778")]
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fn as_slice(&self) -> &[T];
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/// Converts the array to mutable slice
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#[unstable(feature = "fixed_size_array", issue = "27778")]
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fn as_mut_slice(&mut self) -> &mut [T];
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}
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#[unstable(feature = "fixed_size_array", issue = "27778")]
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unsafe impl<T, A: Unsize<[T]>> FixedSizeArray<T> for A {
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#[inline]
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fn as_slice(&self) -> &[T] {
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self
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}
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#[inline]
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fn as_mut_slice(&mut self) -> &mut [T] {
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self
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}
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}
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/// The error type returned when a conversion from a slice to an array fails.
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#[stable(feature = "try_from", since = "1.34.0")]
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#[derive(Debug, Copy, Clone)]
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pub struct TryFromSliceError(());
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#[stable(feature = "core_array", since = "1.36.0")]
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impl fmt::Display for TryFromSliceError {
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#[inline]
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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fmt::Display::fmt(self.__description(), f)
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}
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}
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impl TryFromSliceError {
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#[unstable(feature = "array_error_internals",
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reason = "available through Error trait and this method should not \
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be exposed publicly",
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issue = "0")]
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#[inline]
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#[doc(hidden)]
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pub fn __description(&self) -> &str {
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"could not convert slice to array"
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}
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}
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#[stable(feature = "try_from_slice_error", since = "1.36.0")]
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impl From<Infallible> for TryFromSliceError {
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fn from(x: Infallible) -> TryFromSliceError {
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match x {}
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}
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}
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macro_rules! __impl_slice_eq1 {
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($Lhs: ty, $Rhs: ty) => {
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__impl_slice_eq1! { $Lhs, $Rhs, Sized }
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};
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($Lhs: ty, $Rhs: ty, $Bound: ident) => {
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<'a, 'b, A: $Bound, B> PartialEq<$Rhs> for $Lhs where A: PartialEq<B> {
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#[inline]
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fn eq(&self, other: &$Rhs) -> bool { self[..] == other[..] }
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#[inline]
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fn ne(&self, other: &$Rhs) -> bool { self[..] != other[..] }
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}
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}
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}
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macro_rules! __impl_slice_eq2 {
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($Lhs: ty, $Rhs: ty) => {
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__impl_slice_eq2! { $Lhs, $Rhs, Sized }
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};
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($Lhs: ty, $Rhs: ty, $Bound: ident) => {
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__impl_slice_eq1!($Lhs, $Rhs, $Bound);
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<'a, 'b, A: $Bound, B> PartialEq<$Lhs> for $Rhs where B: PartialEq<A> {
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#[inline]
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fn eq(&self, other: &$Lhs) -> bool { self[..] == other[..] }
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#[inline]
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fn ne(&self, other: &$Lhs) -> bool { self[..] != other[..] }
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}
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}
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}
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// macro for implementing n-element array functions and operations
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macro_rules! array_impls {
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($($N:expr)+) => {
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$(
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<T> AsRef<[T]> for [T; $N] {
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#[inline]
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fn as_ref(&self) -> &[T] {
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&self[..]
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}
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}
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<T> AsMut<[T]> for [T; $N] {
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#[inline]
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fn as_mut(&mut self) -> &mut [T] {
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&mut self[..]
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}
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}
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#[stable(feature = "array_borrow", since = "1.4.0")]
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impl<T> Borrow<[T]> for [T; $N] {
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fn borrow(&self) -> &[T] {
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self
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}
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}
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#[stable(feature = "array_borrow", since = "1.4.0")]
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impl<T> BorrowMut<[T]> for [T; $N] {
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fn borrow_mut(&mut self) -> &mut [T] {
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self
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}
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}
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#[stable(feature = "try_from", since = "1.34.0")]
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impl<T> TryFrom<&[T]> for [T; $N] where T: Copy {
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type Error = TryFromSliceError;
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fn try_from(slice: &[T]) -> Result<[T; $N], TryFromSliceError> {
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<&Self>::try_from(slice).map(|r| *r)
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}
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}
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#[stable(feature = "try_from", since = "1.34.0")]
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impl<'a, T> TryFrom<&'a [T]> for &'a [T; $N] {
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type Error = TryFromSliceError;
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fn try_from(slice: &[T]) -> Result<&[T; $N], TryFromSliceError> {
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if slice.len() == $N {
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let ptr = slice.as_ptr() as *const [T; $N];
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unsafe { Ok(&*ptr) }
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} else {
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Err(TryFromSliceError(()))
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}
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}
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}
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#[stable(feature = "try_from", since = "1.34.0")]
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impl<'a, T> TryFrom<&'a mut [T]> for &'a mut [T; $N] {
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type Error = TryFromSliceError;
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fn try_from(slice: &mut [T]) -> Result<&mut [T; $N], TryFromSliceError> {
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if slice.len() == $N {
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let ptr = slice.as_mut_ptr() as *mut [T; $N];
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unsafe { Ok(&mut *ptr) }
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} else {
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Err(TryFromSliceError(()))
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}
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}
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}
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<T: Hash> Hash for [T; $N] {
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fn hash<H: hash::Hasher>(&self, state: &mut H) {
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Hash::hash(&self[..], state)
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}
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}
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<T: fmt::Debug> fmt::Debug for [T; $N] {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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fmt::Debug::fmt(&&self[..], f)
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}
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}
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<'a, T> IntoIterator for &'a [T; $N] {
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type Item = &'a T;
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type IntoIter = Iter<'a, T>;
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fn into_iter(self) -> Iter<'a, T> {
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self.iter()
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}
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}
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<'a, T> IntoIterator for &'a mut [T; $N] {
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type Item = &'a mut T;
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type IntoIter = IterMut<'a, T>;
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fn into_iter(self) -> IterMut<'a, T> {
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self.iter_mut()
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}
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}
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// NOTE: some less important impls are omitted to reduce code bloat
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__impl_slice_eq1! { [A; $N], [B; $N] }
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__impl_slice_eq2! { [A; $N], [B] }
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__impl_slice_eq2! { [A; $N], &'b [B] }
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__impl_slice_eq2! { [A; $N], &'b mut [B] }
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// __impl_slice_eq2! { [A; $N], &'b [B; $N] }
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// __impl_slice_eq2! { [A; $N], &'b mut [B; $N] }
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<T:Eq> Eq for [T; $N] { }
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<T:PartialOrd> PartialOrd for [T; $N] {
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#[inline]
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fn partial_cmp(&self, other: &[T; $N]) -> Option<Ordering> {
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PartialOrd::partial_cmp(&&self[..], &&other[..])
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}
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#[inline]
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fn lt(&self, other: &[T; $N]) -> bool {
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PartialOrd::lt(&&self[..], &&other[..])
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}
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#[inline]
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fn le(&self, other: &[T; $N]) -> bool {
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PartialOrd::le(&&self[..], &&other[..])
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}
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#[inline]
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fn ge(&self, other: &[T; $N]) -> bool {
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PartialOrd::ge(&&self[..], &&other[..])
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}
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#[inline]
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fn gt(&self, other: &[T; $N]) -> bool {
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PartialOrd::gt(&&self[..], &&other[..])
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}
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}
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<T:Ord> Ord for [T; $N] {
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#[inline]
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fn cmp(&self, other: &[T; $N]) -> Ordering {
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Ord::cmp(&&self[..], &&other[..])
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}
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}
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)+
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}
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}
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array_impls! {
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0 1 2 3 4 5 6 7 8 9
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10 11 12 13 14 15 16 17 18 19
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20 21 22 23 24 25 26 27 28 29
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30 31 32
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}
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// The Default impls cannot be generated using the array_impls! macro because
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// they require array literals.
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macro_rules! array_impl_default {
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{$n:expr, $t:ident $($ts:ident)*} => {
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#[stable(since = "1.4.0", feature = "array_default")]
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impl<T> Default for [T; $n] where T: Default {
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fn default() -> [T; $n] {
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[$t::default(), $($ts::default()),*]
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}
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}
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array_impl_default!{($n - 1), $($ts)*}
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};
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{$n:expr,} => {
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#[stable(since = "1.4.0", feature = "array_default")]
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impl<T> Default for [T; $n] {
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fn default() -> [T; $n] { [] }
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}
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};
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}
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array_impl_default!{32, T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T}

‎src/libcore/lib.rs

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@@ -190,6 +190,7 @@ pub mod borrow;
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/* Core types and methods on primitives */
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pub mod any;
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#[cfg_attr(stage0, path = "array_stage0.rs")]
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pub mod array;
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pub mod ascii;
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pub mod sync;

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