diff --git a/library/core/src/cmp.rs b/library/core/src/cmp.rs index e775ded60f593..e11c2a08d0ebf 100644 --- a/library/core/src/cmp.rs +++ b/library/core/src/cmp.rs @@ -356,8 +356,9 @@ impl Ordering { /// ``` #[inline] #[must_use] + #[rustc_const_stable(feature = "const_ordering", since = "1.48.0")] #[stable(feature = "rust1", since = "1.0.0")] - pub fn reverse(self) -> Ordering { + pub const fn reverse(self) -> Ordering { match self { Less => Greater, Equal => Equal, @@ -394,8 +395,9 @@ impl Ordering { /// ``` #[inline] #[must_use] + #[rustc_const_stable(feature = "const_ordering", since = "1.48.0")] #[stable(feature = "ordering_chaining", since = "1.17.0")] - pub fn then(self, other: Ordering) -> Ordering { + pub const fn then(self, other: Ordering) -> Ordering { match self { Equal => other, _ => self, diff --git a/src/test/ui/consts/const-ordering.rs b/src/test/ui/consts/const-ordering.rs new file mode 100644 index 0000000000000..454f2da00df9e --- /dev/null +++ b/src/test/ui/consts/const-ordering.rs @@ -0,0 +1,15 @@ +// run-pass + +use std::cmp::Ordering; + +// the following methods of core::cmp::Ordering are const: +// - reverse +// - then + +fn main() { + const REVERSE : Ordering = Ordering::Greater.reverse(); + assert_eq!(REVERSE, Ordering::Less); + + const THEN : Ordering = Ordering::Equal.then(REVERSE); + assert_eq!(THEN, Ordering::Less); +}