Updated boost to v1.55.0

[rsem.git] / boost / fusion / iterator / mpl / convert_iterator.hpp

diff --git a/boost/fusion/iterator/mpl/convert_iterator.hpp b/boost/fusion/iterator/mpl/convert_iterator.hpp
new file mode 100644 (file)
index 0000000..dd52d4c
--- /dev/null
+++ b/boost/fusion/iterator/mpl/convert_iterator.hpp
@@ -0,0 +1,58 @@
+/*=============================================================================
+    Copyright (c) 2001-2011 Joel de Guzman
+
+    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)
+==============================================================================*/
+#if !defined(FUSION_CONVERT_ITERATOR_05062005_1218)
+#define FUSION_CONVERT_ITERATOR_05062005_1218
+
+#include <boost/fusion/support/is_iterator.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/mpl/bool.hpp>
+
+namespace boost { namespace fusion
+{
+    template <typename Iterator>
+    struct mpl_iterator; // forward declaration
+
+    //  Test T. If it is a fusion iterator, return a reference to it.
+    //  else, assume it is an mpl iterator.
+
+    template <typename T>
+    struct convert_iterator
+    {
+        typedef typename
+            mpl::if_<
+                is_fusion_iterator<T>
+              , T
+              , mpl_iterator<T>
+            >::type
+        type;
+
+        static T const&
+        call(T const& x, mpl::true_)
+        {
+            return x;
+        }
+
+        static mpl_iterator<T>
+        call(T const& /*x*/, mpl::false_)
+        {
+            return mpl_iterator<T>();
+        }
+
+        static typename
+            mpl::if_<
+                is_fusion_iterator<T>
+              , T const&
+              , mpl_iterator<T>
+            >::type
+        call(T const& x)
+        {
+            return call(x, is_fusion_iterator<T>());
+        }
+    };
+}}
+
+#endif