Expand const impls of PartialEq, Eq, PartialOrd and Ord

library/core/src/alloc/layout.rs

@@ -35,7 +35,8 @@ const fn size_align<T>() -> (usize, usize) {
 /// like this are met, use specific allocators with looser
 /// requirements, or use the more lenient `Allocator` interface.)
 #[stable(feature = "alloc_layout", since = "1.28.0")]
-#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+#[derive(Copy, Clone, Debug, Hash)]
+#[derive_const(PartialEq, Eq)]
 #[lang = "alloc_layout"]
 pub struct Layout {
     // size of the requested block of memory, measured in bytes.
@@ -545,7 +546,8 @@ pub type LayoutErr = LayoutError;
 /// do not satisfy its documented constraints.
 #[stable(feature = "alloc_layout_error", since = "1.50.0")]
 #[non_exhaustive]
-#[derive(Clone, PartialEq, Eq, Debug)]
+#[derive(Clone, Debug)]
+#[derive_const(PartialEq, Eq)]
 pub struct LayoutError;
 
 #[stable(feature = "alloc_layout", since = "1.28.0")]

library/core/src/array/equality.rs

@@ -1,9 +1,10 @@
 use crate::cmp::BytewiseEq;
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T, U, const N: usize> PartialEq<[U; N]> for [T; N]
+#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
+impl<T, U, const N: usize> const PartialEq<[U; N]> for [T; N]
 where
-    T: PartialEq<U>,
+    T: [const] PartialEq<U>,
 {
     #[inline]
     fn eq(&self, other: &[U; N]) -> bool {
@@ -122,14 +123,17 @@ where
 // __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] {}
+#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
+impl<T: [const] Eq, const N: usize> const Eq for [T; N] {}
 
-trait SpecArrayEq<Other, const N: usize>: Sized {
+#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
+const 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 {
+#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
+impl<T: [const] PartialEq<Other>, Other, const N: usize> const SpecArrayEq<Other, N> for T {
     default fn spec_eq(a: &[Self; N], b: &[Other; N]) -> bool {
         a[..] == b[..]
     }
@@ -138,7 +142,8 @@ impl<T: PartialEq<Other>, Other, const N: usize> SpecArrayEq<Other, N> for T {
     }
 }
 
-impl<T: BytewiseEq<U>, U, const N: usize> SpecArrayEq<U, N> for T {
+#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
+impl<T: [const] BytewiseEq<U>, U, const N: usize> const SpecArrayEq<U, N> for T {
     fn spec_eq(a: &[T; N], b: &[U; N]) -> bool {
         // SAFETY: Arrays are compared element-wise, and don't add any padding
         // between elements, so when the elements are `BytewiseEq`, we can

library/core/src/array/mod.rs

@@ -403,7 +403,8 @@ where
 
 /// Implements comparison of arrays [lexicographically](Ord#lexicographical-comparison).
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: PartialOrd, const N: usize> PartialOrd for [T; N] {
+#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
+impl<T: [const] PartialOrd, const N: usize> const PartialOrd for [T; N] {
     #[inline]
     fn partial_cmp(&self, other: &[T; N]) -> Option<Ordering> {
         PartialOrd::partial_cmp(&&self[..], &&other[..])
@@ -428,7 +429,8 @@ impl<T: PartialOrd, const N: usize> PartialOrd for [T; N] {
 
 /// Implements comparison of arrays [lexicographically](Ord#lexicographical-comparison).
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: Ord, const N: usize> Ord for [T; N] {
+#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
+impl<T: [const] Ord, const N: usize> const Ord for [T; N] {
     #[inline]
     fn cmp(&self, other: &[T; N]) -> Ordering {
         Ord::cmp(&&self[..], &&other[..])

library/core/src/ascii/ascii_char.rs

@@ -54,7 +54,8 @@ use crate::{assert_unsafe_precondition, fmt};
 /// [chart]: https://www.unicode.org/charts/PDF/U0000.pdf
 /// [NIST FIPS 1-2]: https://nvlpubs.nist.gov/nistpubs/Legacy/FIPS/fipspub1-2-1977.pdf
 /// [NamesList]: https://www.unicode.org/Public/15.0.0/ucd/NamesList.txt
-#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+#[derive(Copy, Clone, Hash)]
+#[derive_const(Eq, PartialEq, Ord, PartialOrd)]
 #[unstable(feature = "ascii_char", issue = "110998")]
 #[repr(u8)]
 pub enum AsciiChar {

library/core/src/bstr/traits.rs

@@ -6,31 +6,35 @@ use crate::slice::SliceIndex;
 use crate::{hash, ops, range};
 
 #[unstable(feature = "bstr", issue = "134915")]
-impl Ord for ByteStr {
+#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
+impl const Ord for ByteStr {
     #[inline]
     fn cmp(&self, other: &ByteStr) -> Ordering {
         Ord::cmp(&self.0, &other.0)
     }
 }
 
 #[unstable(feature = "bstr", issue = "134915")]
-impl PartialOrd for ByteStr {
+#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
+impl const PartialOrd for ByteStr {
     #[inline]
     fn partial_cmp(&self, other: &ByteStr) -> Option<Ordering> {
         PartialOrd::partial_cmp(&self.0, &other.0)
     }
 }
 
 #[unstable(feature = "bstr", issue = "134915")]
-impl PartialEq<ByteStr> for ByteStr {
+#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
+impl const PartialEq<ByteStr> for ByteStr {
     #[inline]
     fn eq(&self, other: &ByteStr) -> bool {
         &self.0 == &other.0
     }
 }
 
 #[unstable(feature = "bstr", issue = "134915")]
-impl Eq for ByteStr {}
+#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
+impl const Eq for ByteStr {}
 
 #[unstable(feature = "bstr", issue = "134915")]
 impl hash::Hash for ByteStr {

library/core/src/char/mod.rs

@@ -591,7 +591,8 @@ impl fmt::Display for CaseMappingIter {
 
 /// The error type returned when a checked char conversion fails.
 #[stable(feature = "u8_from_char", since = "1.59.0")]
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone)]
+#[derive_const(PartialEq, Eq)]
 pub struct TryFromCharError(pub(crate) ());
 
 #[stable(feature = "u8_from_char", since = "1.59.0")]