diff options
| -rw-r--r-- | library/alloc/src/vec/into_iter.rs | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/library/alloc/src/vec/into_iter.rs b/library/alloc/src/vec/into_iter.rs index b0226c84833..28082143402 100644 --- a/library/alloc/src/vec/into_iter.rs +++ b/library/alloc/src/vec/into_iter.rs @@ -289,6 +289,35 @@ impl<T, A: Allocator> Iterator for IntoIter<T, A> { }; } + fn try_fold<B, F, R>(&mut self, init: B, mut f: F) -> R + where + Self: Sized, + F: FnMut(B, Self::Item) -> R, + R: core::ops::Try<Output = B>, + { + let mut accum = init; + if T::IS_ZST { + while self.ptr.as_ptr() != self.end.cast_mut() { + // SAFETY: we just checked that `self.ptr` is in bounds. + let tmp = unsafe { self.ptr.read() }; + // See `next` for why we subtract from `end` here. + self.end = self.end.wrapping_byte_sub(1); + accum = f(accum, tmp)?; + } + } else { + // SAFETY: `self.end` can only be null if `T` is a ZST. + while self.ptr != non_null!(self.end, T) { + // SAFETY: we just checked that `self.ptr` is in bounds. + let tmp = unsafe { self.ptr.read() }; + // SAFETY: the maximum this can be is `self.end`. + // Increment `self.ptr` first to avoid double dropping in the event of a panic. + self.ptr = unsafe { self.ptr.add(1) }; + accum = f(accum, tmp)?; + } + } + R::from_output(accum) + } + unsafe fn __iterator_get_unchecked(&mut self, i: usize) -> Self::Item where Self: TrustedRandomAccessNoCoerce, |