diff options
| -rw-r--r-- | library/core/src/cmp.rs | 55 |
1 files changed, 49 insertions, 6 deletions
diff --git a/library/core/src/cmp.rs b/library/core/src/cmp.rs index 50b8264bac7..f0fa2e1d2c1 100644 --- a/library/core/src/cmp.rs +++ b/library/core/src/cmp.rs @@ -22,6 +22,7 @@ #![stable(feature = "rust1", since = "1.0.0")] +use crate::const_closure::ConstFnMutClosure; use crate::marker::Destruct; use crate::marker::StructuralPartialEq; @@ -1222,7 +1223,12 @@ pub const fn min<T: ~const Ord + ~const Destruct>(v1: T, v2: T) -> T { #[inline] #[must_use] #[stable(feature = "cmp_min_max_by", since = "1.53.0")] -pub fn min_by<T, F: FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T { +#[rustc_const_unstable(feature = "const_cmp", issue = "92391")] +pub const fn min_by<T, F: ~const FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T +where + T: ~const Destruct, + F: ~const Destruct, +{ match compare(&v1, &v2) { Ordering::Less | Ordering::Equal => v1, Ordering::Greater => v2, @@ -1244,8 +1250,24 @@ pub fn min_by<T, F: FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T { #[inline] #[must_use] #[stable(feature = "cmp_min_max_by", since = "1.53.0")] -pub fn min_by_key<T, F: FnMut(&T) -> K, K: Ord>(v1: T, v2: T, mut f: F) -> T { - min_by(v1, v2, |v1, v2| f(v1).cmp(&f(v2))) +#[rustc_const_unstable(feature = "const_cmp", issue = "92391")] +pub const fn min_by_key<T, F: ~const FnMut(&T) -> K, K: ~const Ord>(v1: T, v2: T, mut f: F) -> T +where + T: ~const Destruct, + F: ~const Destruct, + K: ~const Destruct, +{ + const fn imp<T, F: ~const FnMut(&T) -> K, K: ~const Ord>( + f: &mut F, + (v1, v2): (&T, &T), + ) -> Ordering + where + T: ~const Destruct, + K: ~const Destruct, + { + f(v1).cmp(&f(v2)) + } + min_by(v1, v2, ConstFnMutClosure::new(&mut f, imp)) } /// Compares and returns the maximum of two values. @@ -1286,7 +1308,12 @@ pub const fn max<T: ~const Ord + ~const Destruct>(v1: T, v2: T) -> T { #[inline] #[must_use] #[stable(feature = "cmp_min_max_by", since = "1.53.0")] -pub fn max_by<T, F: FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T { +#[rustc_const_unstable(feature = "const_cmp", issue = "92391")] +pub const fn max_by<T, F: ~const FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T +where + T: ~const Destruct, + F: ~const Destruct, +{ match compare(&v1, &v2) { Ordering::Less | Ordering::Equal => v2, Ordering::Greater => v1, @@ -1308,8 +1335,24 @@ pub fn max_by<T, F: FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T { #[inline] #[must_use] #[stable(feature = "cmp_min_max_by", since = "1.53.0")] -pub fn max_by_key<T, F: FnMut(&T) -> K, K: Ord>(v1: T, v2: T, mut f: F) -> T { - max_by(v1, v2, |v1, v2| f(v1).cmp(&f(v2))) +#[rustc_const_unstable(feature = "const_cmp", issue = "92391")] +pub const fn max_by_key<T, F: ~const FnMut(&T) -> K, K: ~const Ord>(v1: T, v2: T, mut f: F) -> T +where + T: ~const Destruct, + F: ~const Destruct, + K: ~const Destruct, +{ + const fn imp<T, F: ~const FnMut(&T) -> K, K: ~const Ord>( + f: &mut F, + (v1, v2): (&T, &T), + ) -> Ordering + where + T: ~const Destruct, + K: ~const Destruct, + { + f(v1).cmp(&f(v2)) + } + max_by(v1, v2, ConstFnMutClosure::new(&mut f, imp)) } // Implementation of PartialEq, Eq, PartialOrd and Ord for primitive types |