From cd4f96c066117d00c241135d9939fd527809ae8a Mon Sep 17 00:00:00 2001
From: Dan Gohman <sunfish@mozilla.com>
Date: Wed, 2 Jan 2019 11:59:57 -0800
Subject: [PATCH] Use `Vec::with_capacity` when we know the eventual size of
 the `Vec`.

---
 lib/wasm/src/sections_translator.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/wasm/src/sections_translator.rs b/lib/wasm/src/sections_translator.rs
index c1bdda1460..2ee60c19a9 100644
--- a/lib/wasm/src/sections_translator.rs
+++ b/lib/wasm/src/sections_translator.rs
@@ -255,7 +255,7 @@ pub fn parse_element_section<'data>(
             ref s => panic!("unsupported init expr in element section: {:?}", s),
         };
         let items_reader = items.get_items_reader()?;
-        let mut elems = Vec::new();
+        let mut elems = Vec::with_capacity(cast::usize(items_reader.get_count()));
         for item in items_reader {
             let x = item?;
             elems.push(FuncIndex::from_u32(x));