From 86c5faf42bea29da18c82ab0af29b3a8428c5a44 Mon Sep 17 00:00:00 2001
From: "Felix S. Klock II" <pnkfelix@pnkfx.org>
Date: Wed, 8 Apr 2015 13:55:01 +0200
Subject: [PATCH] Address review nit by making `map_id` take an `FnMut`.

---
 src/librustc/middle/region.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/librustc/middle/region.rs b/src/librustc/middle/region.rs
index 727a1dcdfb3..5131322dc41 100644
--- a/src/librustc/middle/region.rs
+++ b/src/librustc/middle/region.rs
@@ -172,8 +172,8 @@ impl CodeExtent {
 
     /// Maps this scope to a potentially new one according to the
     /// NodeId transformer `f_id`.
-    pub fn map_id<F>(&self, f_id: F) -> CodeExtent where
-        F: Fn(ast::NodeId) -> ast::NodeId,
+    pub fn map_id<F>(&self, mut f_id: F) -> CodeExtent where
+        F: FnMut(ast::NodeId) -> ast::NodeId,
     {
         match *self {
             CodeExtent::Misc(node_id) => CodeExtent::Misc(f_id(node_id)),