Merge branches/cpp0x into trunk, enabling a bunch of BOOST_NO_* macros for C++0x early adopter feature tests

[SVN r51444]

test/boost_no_constexpr.ipp

@@ -0,0 +1,23 @@
+//  (C) Copyright Beman Dawes 2008
+
+//  Use, modification and distribution are subject to the
+//  Boost Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+//  See http://www.boost.org/libs/config for more information.
+
+//  MACRO:         BOOST_NO_CONSTEXPR 
+//  TITLE:         C++0x constexpr unavailable
+//  DESCRIPTION:   The compiler does not support C++0x constexpr
+
+namespace boost_no_constexpr {
+
+constexpr int square(int x) { return x * x; }  // from N2235
+
+int test()
+{
+  int i = square(5);
+  return 0;
+}
+
+}