Full merge from trunk at revision 41356 of entire boost-root tree.

[SVN r41370]

old_concept_class_fail.cpp

@@ -0,0 +1,28 @@
+// (C) Copyright Jeremy Siek, David Abrahams 2000-2006.
+// Distributed under 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)
+//
+// Change Log:
+// 20 Jan 2001 - Added warning suppression (David Abrahams)
+
+#include "old_concepts.hpp"
+
+// This file verifies that concepts written the old way still catch
+// errors in class context.  This is not expected to work on compilers
+// without SFINAE support.
+
+struct foo { };
+
+class class_requires_test
+{
+  BOOST_CLASS_REQUIRE(foo, old, EqualityComparableConcept);
+};
+
+int
+main()
+{
+  class_requires_test x;
+  (void)x; // suppress unused variable warning
+  return 0;
+}