diff options
| -rw-r--r-- | components/util/smallvec.rs | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/components/util/smallvec.rs b/components/util/smallvec.rs index 00c43b76b9e..139c1d09300 100644 --- a/components/util/smallvec.rs +++ b/components/util/smallvec.rs @@ -405,6 +405,12 @@ macro_rules! def_small_vector( fn from_iter<I: Iterator<T>>(mut iter: I) -> $name<T> { let mut v = $name::new(); + let (lower_size_bound, _) = iter.size_hint(); + + if lower_size_bound > v.cap() { + v.grow(lower_size_bound); + } + for elem in iter { v.push(elem); } @@ -415,6 +421,14 @@ macro_rules! def_small_vector( impl<T: 'static> Extendable<T> for $name<T> { fn extend<I: Iterator<T>>(&mut self, mut iter: I) { + let (lower_size_bound, _) = iter.size_hint(); + + let target_len = self.len() + lower_size_bound; + + if target_len > self.cap() { + v.grow(target_len); + } + for elem in iter { self.push(elem); } |