From fe005f030abbcdc190dba0ce92d5f07370b82a26 Mon Sep 17 00:00:00 2001
From: John Maddock <john@johnmaddock.co.uk>
Date: Sun, 14 Apr 2013 15:53:05 +0000
Subject: [PATCH] Don't use C++11 only features of std::string.

[SVN r83900]
---
 include/boost/multiprecision/detail/float_string_cvt.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/boost/multiprecision/detail/float_string_cvt.hpp b/include/boost/multiprecision/detail/float_string_cvt.hpp
index b7864ea3..6c1f323e 100644
--- a/include/boost/multiprecision/detail/float_string_cvt.hpp
+++ b/include/boost/multiprecision/detail/float_string_cvt.hpp
@@ -137,7 +137,7 @@ std::string convert_to_string(Backend b, std::streamsize digits, std::ios_base::
          if((cdigit == 5) && (t.compare(ui_type(0)) == 0))
          {
             // Bankers rounding:
-            if((result.back() - '0') & 1)
+            if((*result.rend() - '0') & 1)
             {
                round_string_up_at(result, result.size() - 1);
             }