From b6040ac324814c5122d88a2b10cf9a569944f3f4 Mon Sep 17 00:00:00 2001
From: Dane Springmeyer <dane@dbsgeo.com>
Date: Sun, 15 Sep 2013 21:12:12 -0700
Subject: [PATCH] correct return type from std::string::substr

---
 src/image_util.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/image_util.cpp b/src/image_util.cpp
index 840ae0f6b..8cee4dd7d 100644
--- a/src/image_util.cpp
+++ b/src/image_util.cpp
@@ -206,7 +206,7 @@ void handle_png_options(std::string const& type,
             }
             else if (boost::algorithm::starts_with(t, "s="))
             {
-                std::string const& s = t.substr(2);
+                std::string s = t.substr(2);
                 if (s == "default")
                 {
                     *strategy = Z_DEFAULT_STRATEGY;
@@ -441,7 +441,7 @@ void save_to_stream(T const& image,
         {
 #if defined(HAVE_JPEG)
             int quality = 85;
-            std::string const& val = t.substr(4);
+            std::string val = t.substr(4);
             if (!val.empty())
             {
                 if (!mapnik::util::string2int(val,quality) || quality < 0 || quality > 100)