1 files changed, 117 insertions, 0 deletions
diff --git a/boost/fusion/support/deduce.hpp b/boost/fusion/support/deduce.hpp
new file mode 100644
index 0000000000..3a7231bdf1
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+++ b/boost/fusion/support/deduce.hpp
@@ -0,0 +1,117 @@
+/*=============================================================================
+    Copyright (c) 2007 Tobias Schwinger
+  
+    Use modification and distribution are 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(BOOST_FUSION_SUPPORT_DEDUCE_HPP_INCLUDED)
+#define BOOST_FUSION_SUPPORT_DEDUCE_HPP_INCLUDED
+
+#include <boost/ref.hpp>
+
+namespace boost { namespace fusion { namespace traits
+{
+    template <typename T> struct deduce;
+
+    //----- ---- --- -- - -  -   -
+
+    // Non-references pass unchanged
+
+    template <typename T>
+    struct deduce
+    {
+        typedef T type; 
+    };
+
+    template <typename T>
+    struct deduce<T const>
+    {
+        typedef T type;
+    };
+
+    template <typename T>
+    struct deduce<T volatile>
+    {
+        typedef T type;
+    };
+
+    template <typename T>
+    struct deduce<T const volatile>
+    {
+        typedef T type;
+    };
+
+    // Keep references on mutable LValues
+
+    template <typename T>
+    struct deduce<T &>
+    {
+        typedef T & type;
+    };
+
+    template <typename T>
+    struct deduce<T volatile&>
+    {
+        typedef T volatile& type;
+    };
+
+    // Store away potential RValues
+
+    template <typename T>
+    struct deduce<T const&>
+    {
+        typedef T type;
+    };
+
+    template <typename T>
+    struct deduce<T const volatile&>
+    {
+        typedef T type;
+    };
+
+    // Unwrap Boost.RefS (referencee cv is deduced)
+
+    template <typename T>
+    struct deduce<reference_wrapper<T> & >
+    {
+        typedef T& type;
+    };
+
+    template <typename T>
+    struct deduce<reference_wrapper<T> const & >
+    {
+        typedef T& type;
+    };
+
+    // Keep references on arrays, even if const
+
+    template <typename T, int N>
+    struct deduce<T(&)[N]>
+    {
+        typedef T(&type)[N];
+    };
+
+    template <typename T, int N>
+    struct deduce<volatile T(&)[N]>
+    {
+        typedef volatile T(&type)[N]; 
+    };
+
+    template <typename T, int N>
+    struct deduce<const T(&)[N]>
+    {
+        typedef const T(&type)[N];
+    };
+
+    template <typename T, int N>
+    struct deduce<const volatile T(&)[N]>
+    {
+        typedef const volatile T(&type)[N];
+    };
+
+}}}
+
+#endif
+