diff options
| -rw-r--r-- | src/libcore/iter/mod.rs | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/src/libcore/iter/mod.rs b/src/libcore/iter/mod.rs index 443b1567e1b..33c00989fd2 100644 --- a/src/libcore/iter/mod.rs +++ b/src/libcore/iter/mod.rs @@ -698,13 +698,16 @@ impl<I> Iterator for StepBy<I> where I: Iterator { #[inline] fn nth(&mut self, mut n: usize) -> Option<Self::Item> { if self.first_take { + self.first_take = false; + let first = self.iter.next(); if n == 0 { - self.first_take = false; - return self.iter.next() + return first; } n -= 1; } - self.iter.nth(n * self.step) + // n and self.step are indices, thus we need to add 1 before multiplying. + // After that we need to subtract 1 from the result to convert it back to an index. + self.iter.nth((n + 1) * (self.step + 1) - 1) } } |