Initial move from Spirit CVS

[SVN r34896]

include/boost/fusion/algorithm/query/detail/count.hpp

@@ -0,0 +1,69 @@
+/*=============================================================================
+    Copyright (c) 2001-2006 Joel de Guzman
+
+    Use, modification and distribution is 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)
+==============================================================================*/
+#if !defined(FUSION_COUNT_09162005_0158)
+#define FUSION_COUNT_09162005_0158
+
+#include <boost/mpl/or.hpp>
+#include <boost/type_traits/is_convertible.hpp>
+#include <boost/fusion/support/detail/access.hpp>
+
+namespace boost { namespace fusion { namespace detail
+{ 
+    template <bool is_convertible>
+    struct compare_convertible;
+
+    // T1 is convertible to T2 or vice versa
+    template <>
+    struct compare_convertible<true> 
+    {
+        template <typename T1, typename T2>
+        static bool
+        call(T1 const& x, T2 const& y)
+        {
+            return x == y;
+        }
+    };
+
+    // T1 is NOT convertible to T2 NOR vice versa
+    template <>
+    struct compare_convertible<false>
+    {
+        template <typename T1, typename T2>
+        static bool
+        call(T1 const&, T2 const&)
+        {
+            return false;
+        }
+    };
+
+    template <typename T1>
+    struct count_compare
+    {
+        typedef typename detail::call_param<T1>::type param;
+        count_compare(param x)
+            : x(x) {}
+
+        template <typename T2>
+        bool
+        operator()(T2 const& y)
+        {
+            return 
+                compare_convertible<
+                    mpl::or_<
+                        is_convertible<T1, T2>
+                      , is_convertible<T2, T1> 
+                    >::value
+                >::call(x, y);
+        }
+
+        param x;
+    };
+}}}
+
+#endif
+