Fix default implementation of has_push_back and has_push_front

[SVN r54948]
2009-07-14 16:49:45 +00:00
parent 78364897a1
commit 1ba6d35b4d
5 changed files with 73 additions and 12 deletions
@@ -0,0 +1,52 @@
+
+// Copyright Steven Watanabe 2009
+//
+// 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)
+//
+// See http://www.boost.org/libs/mpl for documentation.
+
+// $Id$
+// $Date: 2008-10-10 02:21:07 -0700 (Fri, 10 Oct 2008) $
+// $Revision: 49240 $
+
+#include <boost/mpl/push_back.hpp>
+
+#include <boost/mpl/aux_/test.hpp>
+
+struct no_push_back_tag {};
+
+struct no_push_back
+{
+    typedef no_push_back_tag tag;
+};
+
+struct has_push_back_tag {};
+
+struct with_push_back
+{
+    typedef has_push_back_tag tag;
+};
+
+namespace boost { namespace mpl {
+
+template<>
+struct push_back_impl< has_push_back_tag >
+{
+    template<class Seq, class T> struct apply
+    {
+        typedef no_push_back type;
+    };
+};
+
+}}
+
+MPL_TEST_CASE()
+{
+    MPL_ASSERT_NOT(( has_push_back< no_push_back > ));
+    MPL_ASSERT(( has_push_back< with_push_back > ));
+
+    typedef push_back< with_push_back , int >::type test;
+    MPL_ASSERT(( is_same< test, no_push_back > ));
+}