Get <boost/functional/hash/extensions.hpp> to work.

[SVN r54142]

test/Jamfile.v2

@@ -36,6 +36,7 @@ test-suite functional/hash
         [ run hash_complex_test.cpp ]
         [ run link_test.cpp link_test_2.cpp ]
         [ run link_ext_test.cpp link_no_ext_test.cpp ]
+        [ run extensions_hpp_test.cpp ]
         [ run container_fwd_test.cpp ]
         [ compile-fail hash_no_ext_fail_test.cpp ]
         [ compile-fail namespace_fail_test.cpp ]

test/extensions_hpp_test.cpp

@@ -0,0 +1,17 @@
+
+// Copyright 2009 Daniel James.
+// 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)
+
+// Check that boost/functional/hash/extensions.hpp works okay.
+//
+// It probably should be in boost/functional/hash/detail, but since it isn't it
+// should work.
+
+#include <boost/functional/hash/extensions.hpp>
+
+int main() {
+    int x[2] = { 2, 3 };
+    boost::hash<int[2]> hf;
+    hf(x);
+}