diff options
| -rw-r--r-- | library/core/src/slice/mod.rs | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/library/core/src/slice/mod.rs b/library/core/src/slice/mod.rs index 2c699ee9fdd..5bb7243c449 100644 --- a/library/core/src/slice/mod.rs +++ b/library/core/src/slice/mod.rs @@ -4445,8 +4445,10 @@ impl<T> [T] { /// ``` #[inline] #[stable(feature = "slice_take", since = "CURRENT_RUSTC_VERSION")] - pub fn split_off_first<'a>(self: &mut &'a Self) -> Option<&'a T> { - let (first, rem) = self.split_first()?; + #[rustc_const_unstable(feature = "const_split_off_first_last", issue = "138539")] + pub const fn split_off_first<'a>(self: &mut &'a Self) -> Option<&'a T> { + // FIXME(const-hack): Use `?` when available in const instead of `let-else`. + let Some((first, rem)) = self.split_first() else { return None }; *self = rem; Some(first) } @@ -4468,8 +4470,11 @@ impl<T> [T] { /// ``` #[inline] #[stable(feature = "slice_take", since = "CURRENT_RUSTC_VERSION")] - pub fn split_off_first_mut<'a>(self: &mut &'a mut Self) -> Option<&'a mut T> { - let (first, rem) = mem::take(self).split_first_mut()?; + #[rustc_const_unstable(feature = "const_split_off_first_last", issue = "138539")] + pub const fn split_off_first_mut<'a>(self: &mut &'a mut Self) -> Option<&'a mut T> { + // FIXME(const-hack): Use `mem::take` and `?` when available in const. + // Original: `mem::take(self).split_first_mut()?` + let Some((first, rem)) = mem::replace(self, &mut []).split_first_mut() else { return None }; *self = rem; Some(first) } @@ -4490,8 +4495,10 @@ impl<T> [T] { /// ``` #[inline] #[stable(feature = "slice_take", since = "CURRENT_RUSTC_VERSION")] - pub fn split_off_last<'a>(self: &mut &'a Self) -> Option<&'a T> { - let (last, rem) = self.split_last()?; + #[rustc_const_unstable(feature = "const_split_off_first_last", issue = "138539")] + pub const fn split_off_last<'a>(self: &mut &'a Self) -> Option<&'a T> { + // FIXME(const-hack): Use `?` when available in const instead of `let-else`. + let Some((last, rem)) = self.split_last() else { return None }; *self = rem; Some(last) } @@ -4513,8 +4520,11 @@ impl<T> [T] { /// ``` #[inline] #[stable(feature = "slice_take", since = "CURRENT_RUSTC_VERSION")] - pub fn split_off_last_mut<'a>(self: &mut &'a mut Self) -> Option<&'a mut T> { - let (last, rem) = mem::take(self).split_last_mut()?; + #[rustc_const_unstable(feature = "const_split_off_first_last", issue = "138539")] + pub const fn split_off_last_mut<'a>(self: &mut &'a mut Self) -> Option<&'a mut T> { + // FIXME(const-hack): Use `mem::take` and `?` when available in const. + // Original: `mem::take(self).split_last_mut()?` + let Some((last, rem)) = mem::replace(self, &mut []).split_last_mut() else { return None }; *self = rem; Some(last) } |