blob: ddbbb0ce21d29454555bd7bdcdb0502e9639085f [file] [log] [blame]
// (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 NDNBOOST_OB_CALL_TRAITS_HPP
#define NDNBOOST_OB_CALL_TRAITS_HPP
#ifndef NDNBOOST_CONFIG_HPP
#include <ndnboost/config.hpp>
#endif
#ifndef NDNBOOST_ARITHMETIC_TYPE_TRAITS_HPP
#include <ndnboost/type_traits/arithmetic_traits.hpp>
#endif
#ifndef NDNBOOST_COMPOSITE_TYPE_TRAITS_HPP
#include <ndnboost/type_traits/composite_traits.hpp>
#endif
namespace ndnboost{
#ifdef NDNBOOST_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<
::ndnboost::is_pointer<T>::value,
::ndnboost::is_arithmetic<T>::value,
::ndnboost::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 // NDNBOOST_OB_CALL_TRAITS_HPP