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| author | Mazdak Farrokhzad <twingoow@gmail.com> | 2019-06-20 08:35:58 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2019-06-20 08:35:58 +0200 |
| commit | 3e08f1b57ea6df87ee2d01f31339958998f8ea26 (patch) | |
| tree | 59ff79d60280f87ec16e094fa01bcc36f2ecbb43 /src/libcore/iter | |
| parent | 3c805ce183840bd20bd81a54a02b3c8b6dccc9dd (diff) | |
| parent | e80a37558df5ac9828caccd48459fdb7be488f5b (diff) | |
| download | rust-3e08f1b57ea6df87ee2d01f31339958998f8ea26.tar.gz rust-3e08f1b57ea6df87ee2d01f31339958998f8ea26.zip | |
Rollup merge of #60454 - acrrd:issues/54054_skip, r=scottmcm
Add custom nth_back to Skip Implementation of nth_back for Skip. Part of #54054
Diffstat (limited to 'src/libcore/iter')
| -rw-r--r-- | src/libcore/iter/adapters/mod.rs | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/libcore/iter/adapters/mod.rs b/src/libcore/iter/adapters/mod.rs index 518442efe74..c2edcd22f95 100644 --- a/src/libcore/iter/adapters/mod.rs +++ b/src/libcore/iter/adapters/mod.rs @@ -1509,6 +1509,20 @@ impl<I> DoubleEndedIterator for Skip<I> where I: DoubleEndedIterator + ExactSize } } + #[inline] + fn nth_back(&mut self, n: usize) -> Option<I::Item> { + let len = self.len(); + if n < len { + self.iter.nth_back(n) + } else { + if len > 0 { + // consume the original iterator + self.iter.nth_back(len-1); + } + None + } + } + fn try_rfold<Acc, Fold, R>(&mut self, init: Acc, mut fold: Fold) -> R where Self: Sized, Fold: FnMut(Acc, Self::Item) -> R, R: Try<Ok=Acc> { |