diff options
| -rw-r--r-- | library/alloc/src/vec/mod.rs | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs index d52c78eedf3..4989244b50e 100644 --- a/library/alloc/src/vec/mod.rs +++ b/library/alloc/src/vec/mod.rs @@ -1445,6 +1445,34 @@ impl<T, A: Allocator> Vec<T, A> { where F: FnMut(&T) -> bool, { + self.retain_mut(|elem| f(elem)); + } + + /// Retains only the elements specified by the predicate, passing a mutable reference to it. + /// + /// In other words, remove all elements `e` such that `f(&mut e)` returns `false`. + /// This method operates in place, visiting each element exactly once in the + /// original order, and preserves the order of the retained elements. + /// + /// # Examples + /// + /// ``` + /// #![feature(vec_retain_mut)] + /// + /// let mut vec = vec![1, 2, 3, 4]; + /// vec.retain_mut(|x| if *x > 3 { + /// false + /// } else { + /// *x += 1; + /// true + /// }); + /// assert_eq!(vec, [2, 3, 4]); + /// ``` + #[unstable(feature = "vec_retain_mut", issue = "90829")] + pub fn retain_mut<F>(&mut self, mut f: F) + where + F: FnMut(&mut T) -> bool, + { let original_len = self.len(); // Avoid double drop if the drop guard is not executed, // since we may make some holes during the process. @@ -1496,7 +1524,7 @@ impl<T, A: Allocator> Vec<T, A> { g: &mut BackshiftOnDrop<'_, T, A>, ) -> bool where - F: FnMut(&T) -> bool, + F: FnMut(&mut T) -> bool, { // SAFETY: Unchecked element must be valid. let cur = unsafe { &mut *g.v.as_mut_ptr().add(g.processed_len) }; |