diff --git a/library/core/src/cmp.rs b/library/core/src/cmp.rs index 3953c73319fe4..dde442aa7b52d 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/library/core/tests/cmp.rs b/library/core/tests/cmp.rs index 4086917780fa4..835289daf715a 100644 --- a/library/core/tests/cmp.rs +++ b/library/core/tests/cmp.rs @@ -1,4 +1,7 @@ -use core::cmp::{self, Ordering::*}; +use core::cmp::{ + self, + Ordering::{self, *}, +}; #[test] fn test_int_totalord() { @@ -116,3 +119,16 @@ fn test_user_defined_eq() { assert!(SketchyNum { num: 37 } == SketchyNum { num: 34 }); assert!(SketchyNum { num: 25 } != SketchyNum { num: 57 }); } + +#[test] +fn ordering_const() { + // test that the methods of `Ordering` are usable in a const context + + const ORDERING: Ordering = Greater; + + const REVERSE: Ordering = ORDERING.reverse(); + assert_eq!(REVERSE, Less); + + const THEN: Ordering = Equal.then(ORDERING); + assert_eq!(THEN, Greater); +}