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+// (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000.
+// 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).
+//
+// See http://www.boost.org/libs/utility for most recent version including documentation.
+//
+// Crippled version for crippled compilers:
+// see libs/utility/call_traits.htm
+//
+
+/* Release notes:
+ 01st October 2000:
+ Fixed call_traits on VC6, using "poor man's partial specialisation",
+ using ideas taken from "Generative programming" by Krzysztof Czarnecki
+ & Ulrich Eisenecker.
+*/
+
+#ifndef BOOST_OB_CALL_TRAITS_HPP
+#define BOOST_OB_CALL_TRAITS_HPP
+
+#ifndef BOOST_CONFIG_HPP
+#include <boost/config.hpp>
+#endif
+
+#ifndef BOOST_ARITHMETIC_TYPE_TRAITS_HPP
+#include <boost/type_traits/arithmetic_traits.hpp>
+#endif
+#ifndef BOOST_COMPOSITE_TYPE_TRAITS_HPP
+#include <boost/type_traits/composite_traits.hpp>
+#endif
+
+namespace boost{
+
+#ifdef BOOST_MSVC6_MEMBER_TEMPLATES
+//
+// use member templates to emulate
+// partial specialisation:
+//
+namespace detail{
+
+template <class T>
+struct standard_call_traits
+{
+ typedef T value_type;
+ typedef T& reference;
+ typedef const T& const_reference;
+ typedef const T& param_type;
+};
+template <class T>
+struct simple_call_traits
+{
+ typedef T value_type;
+ typedef T& reference;
+ typedef const T& const_reference;
+ typedef const T param_type;
+};
+template <class T>
+struct reference_call_traits
+{
+ typedef T value_type;
+ typedef T reference;
+ typedef T const_reference;
+ typedef T param_type;
+};
+
+template <bool pointer, bool arithmetic, bool reference>
+struct call_traits_chooser
+{
+ template <class T>
+ struct rebind
+ {
+ typedef standard_call_traits<T> type;
+ };
+};
+
+template <>
+struct call_traits_chooser<true, false, false>
+{
+ template <class T>
+ struct rebind
+ {
+ typedef simple_call_traits<T> type;
+ };
+};
+
+template <>
+struct call_traits_chooser<false, false, true>
+{
+ template <class T>
+ struct rebind
+ {
+ typedef reference_call_traits<T> type;
+ };
+};
+
+template <bool size_is_small>
+struct call_traits_sizeof_chooser2
+{
+ template <class T>
+ struct small_rebind
+ {
+ typedef simple_call_traits<T> small_type;
+ };
+};
+
+template<>
+struct call_traits_sizeof_chooser2<false>
+{
+ template <class T>
+ struct small_rebind
+ {
+ typedef standard_call_traits<T> small_type;
+ };
+};
+
+template <>
+struct call_traits_chooser<false, true, false>
+{
+ template <class T>
+ struct rebind
+ {
+ enum { sizeof_choice = (sizeof(T) <= sizeof(void*)) };
+ typedef call_traits_sizeof_chooser2<(sizeof(T) <= sizeof(void*))> chooser;
+ typedef typename chooser::template small_rebind<T> bound_type;
+ typedef typename bound_type::small_type type;
+ };
+};
+
+} // namespace detail
+template <typename T>
+struct call_traits
+{
+private:
+ typedef detail::call_traits_chooser<
+ ::boost::is_pointer<T>::value,
+ ::boost::is_arithmetic<T>::value,
+ ::boost::is_reference<T>::value
+ > chooser;
+ typedef typename chooser::template rebind<T> bound_type;
+ typedef typename bound_type::type call_traits_type;
+public:
+ typedef typename call_traits_type::value_type value_type;
+ typedef typename call_traits_type::reference reference;
+ typedef typename call_traits_type::const_reference const_reference;
+ typedef typename call_traits_type::param_type param_type;
+};
+
+#else
+//
+// sorry call_traits is completely non-functional
+// blame your broken compiler:
+//
+
+template <typename T>
+struct call_traits
+{
+ typedef T value_type;
+ typedef T& reference;
+ typedef const T& const_reference;
+ typedef const T& param_type;
+};
+
+#endif // member templates
+
+}
+
+#endif // BOOST_OB_CALL_TRAITS_HPP