perf(allocator): use capacity hint (#4584)

oxc-project · Jul 31, 2024 · 4c6d19d · 4c6d19d
1 parent 1aea15c
commit 4c6d19d
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/crates/oxc_allocator/src/arena.rs b/crates/oxc_allocator/src/arena.rs
@@ -124,7 +124,9 @@ impl<'alloc, T> Vec<'alloc, T> {
 
     #[inline]
     pub fn from_iter_in<I: IntoIterator<Item = T>>(iter: I, allocator: &'alloc Allocator) -> Self {
-        let mut vec = vec::Vec::new_in(&**allocator);
+        let iter = iter.into_iter();
+        let capacity = iter.size_hint().1.unwrap_or(0);
+        let mut vec = vec::Vec::with_capacity_in(capacity, &**allocator);
         vec.extend(iter);
         Self(vec)
     }