diff options
Diffstat (limited to 'library/alloc/src/collections/vec_deque/iter.rs')
-rw-r--r-- | library/alloc/src/collections/vec_deque/iter.rs | 33 |
1 files changed, 18 insertions, 15 deletions
diff --git a/library/alloc/src/collections/vec_deque/iter.rs b/library/alloc/src/collections/vec_deque/iter.rs index d9f393714..646a2a991 100644 --- a/library/alloc/src/collections/vec_deque/iter.rs +++ b/library/alloc/src/collections/vec_deque/iter.rs @@ -1,4 +1,5 @@ use core::iter::{FusedIterator, TrustedLen, TrustedRandomAccess, TrustedRandomAccessNoCoerce}; +use core::num::NonZeroUsize; use core::ops::Try; use core::{fmt, mem, slice}; @@ -55,13 +56,15 @@ impl<'a, T> Iterator for Iter<'a, T> { } } - fn advance_by(&mut self, n: usize) -> Result<(), usize> { - let m = match self.i1.advance_by(n) { - Ok(_) => return Ok(()), - Err(m) => m, - }; - mem::swap(&mut self.i1, &mut self.i2); - self.i1.advance_by(n - m).map_err(|o| o + m) + fn advance_by(&mut self, n: usize) -> Result<(), NonZeroUsize> { + let remaining = self.i1.advance_by(n); + match remaining { + Ok(()) => return Ok(()), + Err(n) => { + mem::swap(&mut self.i1, &mut self.i2); + self.i1.advance_by(n.get()) + } + } } #[inline] @@ -125,14 +128,14 @@ impl<'a, T> DoubleEndedIterator for Iter<'a, T> { } } - fn advance_back_by(&mut self, n: usize) -> Result<(), usize> { - let m = match self.i2.advance_back_by(n) { - Ok(_) => return Ok(()), - Err(m) => m, - }; - - mem::swap(&mut self.i1, &mut self.i2); - self.i2.advance_back_by(n - m).map_err(|o| m + o) + fn advance_back_by(&mut self, n: usize) -> Result<(), NonZeroUsize> { + match self.i2.advance_back_by(n) { + Ok(()) => return Ok(()), + Err(n) => { + mem::swap(&mut self.i1, &mut self.i2); + self.i2.advance_back_by(n.get()) + } + } } fn rfold<Acc, F>(self, accum: Acc, mut f: F) -> Acc |