diff --git a/src/libcore/iter/iterator.rs b/src/libcore/iter/iterator.rs index 6a4dba31b62a9..40298389c1ac7 100644 --- a/src/libcore/iter/iterator.rs +++ b/src/libcore/iter/iterator.rs @@ -253,8 +253,12 @@ pub trait Iterator { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] - fn nth(&mut self, n: usize) -> Option { - self.spec_nth(n) + fn nth(&mut self, mut n: usize) -> Option { + for x in self { + if n == 0 { return Some(x) } + n -= 1; + } + None } /// Creates an iterator starting at the same point, but stepping by @@ -2381,27 +2385,3 @@ impl<'a, I: Iterator + ?Sized> Iterator for &'a mut I { (**self).nth(n) } } - - -trait SpecIterator : Iterator { - fn spec_nth(&mut self, n: usize) -> Option; -} - -impl SpecIterator for I { - default fn spec_nth(&mut self, mut n: usize) -> Option { - for x in self { - if n == 0 { return Some(x) } - n -= 1; - } - None - } -} - -impl SpecIterator for I { - fn spec_nth(&mut self, n: usize) -> Option { - self.try_fold(n, move |i, x| { - if i == 0 { LoopState::Break(x) } - else { LoopState::Continue(i - 1) } - }).break_value() - } -}