From 3ae6668b44232b1b16b93c8b7f53bac5f11ff81c Mon Sep 17 00:00:00 2001
From: David Deakins <DavidDeakins@gmail.com>
Date: Wed, 8 Apr 2009 16:38:38 +0000
Subject: [PATCH] After including <cstddef> to check for usage of STLport, if
 STLport is not detected, then include <utility> to detect other std libs. 
 This avoids the issue that some std libs do not include all of their
 C++-related macros when just <cstddef> is included.  Related to issue #2924.

[SVN r52262]
---
 include/boost/config/select_stdlib_config.hpp | 23 +++++++++++++------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/include/boost/config/select_stdlib_config.hpp b/include/boost/config/select_stdlib_config.hpp
index 71a7a06a..9c970667 100644
--- a/include/boost/config/select_stdlib_config.hpp
+++ b/include/boost/config/select_stdlib_config.hpp
@@ -11,12 +11,9 @@
 
 // locate which std lib we are using and define BOOST_STDLIB_CONFIG as needed:
 
-// we need to include a std lib header here in order to detect which
-// library is in use, use <cstddef> as it's one of the smaller std lib headers 
-// - do not rely on this header being included -
-// users can short-circuit this header if they know whose std lib
-// they are using.
-
+// First include <cstddef> to determine if some version of STLport is in use as the std lib
+// (do not rely on this header being included since users can short-circuit this header 
+//  if they know whose std lib they are using.)
 #include <cstddef>
 
 #if defined(__SGI_STL_PORT) || defined(_STLPORT_VERSION)
@@ -25,7 +22,17 @@
 // can end up detecting that first rather than STLport:
 #  define BOOST_STDLIB_CONFIG "boost/config/stdlib/stlport.hpp"
 
-#elif defined(__LIBCOMO__)
+#else
+
+// If our std lib was not some version of STLport, then include <utility> as it is about 
+// the smallest of the std lib headers that includes real C++ stuff.  (Some std libs do not
+// include their C++-related macros in <cstddef> so this additional include makes sure
+// we get those definitions)
+// (again do not rely on this header being included since users can short-circuit this 
+//  header if they know whose std lib they are using.)
+#include <boost/config/no_tr1/utility.hpp>
+
+#if defined(__LIBCOMO__)
 // Comeau STL:
 #define BOOST_STDLIB_CONFIG "boost/config/stdlib/libcomo.hpp"
 
@@ -64,5 +71,7 @@
 
 #endif
 
+#endif
+