From 367f3cd5d3ff712c1a74fc5637056ce353c8ad33 Mon Sep 17 00:00:00 2001
From: Dan Gohman <sunfish@mozilla.com>
Date: Mon, 19 Nov 2018 07:04:38 -0600
Subject: [PATCH] Implement `reserve` and `reserve_exact` for `PrimaryMap`.

---
 lib/entity/src/primary.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/entity/src/primary.rs b/lib/entity/src/primary.rs
index e23e8e2a6b..9b87098239 100644
--- a/lib/entity/src/primary.rs
+++ b/lib/entity/src/primary.rs
@@ -111,6 +111,16 @@ where
     pub fn last(&self) -> Option<&V> {
         self.elems.last()
     }
+
+    /// Reserves capacity for at least `additional` more elements to be inserted.
+    pub fn reserve(&mut self, additional: usize) {
+        self.elems.reserve(additional)
+    }
+
+    /// Reserves the minimum capacity for exactly `additional` more elements to be inserted.
+    pub fn reserve_exact(&mut self, additional: usize) {
+        self.elems.reserve_exact(additional)
+    }
 }
 
 /// Immutable indexing into an `PrimaryMap`.