From 50c4506329673d38b3170f048f546a5885dd8310 Mon Sep 17 00:00:00 2001
From: gnzlbg <gonzalobg88@gmail.com>
Date: Mon, 14 May 2018 13:58:28 +0200
Subject: [PATCH] Switch Vec from doubling size on growth to using RawVec's
 reserve

On growth, Vec does not require to exactly double its size for correctness,
like, for example, VecDeque does.

Using reserve instead better expresses this intent. It also allows to reuse
Excess capacity on growth and for better growth-policies to be provided by
RawVec.
---
 src/liballoc/vec.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
index 690cbcb559b..ffaff20bcc9 100644
--- a/src/liballoc/vec.rs
+++ b/src/liballoc/vec.rs
@@ -840,7 +840,7 @@ impl<T> Vec<T> {
 
         // space for the new element
         if len == self.buf.cap() {
-            self.buf.double();
+            self.reserve(1);
         }
 
         unsafe {
@@ -1060,7 +1060,7 @@ impl<T> Vec<T> {
         // This will panic or abort if we would allocate > isize::MAX bytes
         // or if the length increment would overflow for zero-sized types.
         if self.len == self.buf.cap() {
-            self.buf.double();
+            self.reserve(1);
         }
         unsafe {
             let end = self.as_mut_ptr().offset(self.len as isize);