104 lines
3.3 KiB
C++
Executable File
104 lines
3.3 KiB
C++
Executable File
/*-----------------------------------------------------------------------------+
|
|
Copyright (c) 2008-2009: Joachim Faulhaber
|
|
+------------------------------------------------------------------------------+
|
|
Distributed under the Boost Software License, Version 1.0.
|
|
(See accompanying file LICENCE.txt or copy at
|
|
http://www.boost.org/LICENSE_1_0.txt)
|
|
+-----------------------------------------------------------------------------*/
|
|
#ifndef BOOST_ICL_TYPE_TRAITS_DIFFERENCE_TYPE_OF_HPP_JOFA_080911
|
|
#define BOOST_ICL_TYPE_TRAITS_DIFFERENCE_TYPE_OF_HPP_JOFA_080911
|
|
|
|
#include <boost/config.hpp> // For macro BOOST_STATIC_CONSTANT
|
|
#include <boost/type_traits/is_pointer.hpp>
|
|
#include <boost/mpl/has_xxx.hpp>
|
|
#include <boost/mpl/or.hpp>
|
|
#include <boost/mpl/and.hpp>
|
|
#include <boost/mpl/not.hpp>
|
|
#include <boost/icl/type_traits/no_type.hpp>
|
|
#include <boost/icl/type_traits/is_numeric.hpp>
|
|
#include <boost/icl/type_traits/rep_type_of.hpp>
|
|
|
|
namespace boost{ namespace icl
|
|
{
|
|
namespace detail
|
|
{
|
|
BOOST_MPL_HAS_XXX_TRAIT_DEF(difference_type)
|
|
}
|
|
|
|
//--------------------------------------------------------------------------
|
|
template <class Type>
|
|
struct has_difference_type
|
|
: mpl::bool_<detail::has_difference_type<Type>::value>
|
|
{};
|
|
|
|
//--------------------------------------------------------------------------
|
|
template<class Type> // type_of(T-T)==T
|
|
struct is_subtraction_closed
|
|
{
|
|
typedef is_subtraction_closed type;
|
|
BOOST_STATIC_CONSTANT(bool,
|
|
value = (mpl::or_< is_numeric<Type>
|
|
, mpl::and_< has_rep_type<Type>
|
|
, mpl::not_<has_difference_type<Type> >
|
|
>
|
|
>::value)
|
|
);
|
|
};
|
|
|
|
//--------------------------------------------------------------------------
|
|
template<class Type>
|
|
struct has_difference
|
|
{
|
|
typedef has_difference type;
|
|
BOOST_STATIC_CONSTANT(bool,
|
|
value = (mpl::or_< is_subtraction_closed<Type>
|
|
, is_pointer<Type>
|
|
, has_difference_type<Type> >::value)
|
|
);
|
|
};
|
|
|
|
//--------------------------------------------------------------------------
|
|
template <class Type, bool has_difference, bool has_diff_type>
|
|
struct get_difference_type;
|
|
|
|
template <class Type>
|
|
struct get_difference_type<Type, false, false>
|
|
{
|
|
typedef no_type type;
|
|
};
|
|
|
|
template <class Type>
|
|
struct get_difference_type<Type*, true, false>
|
|
{
|
|
typedef std::ptrdiff_t type;
|
|
};
|
|
|
|
template <class Type>
|
|
struct get_difference_type<Type, true, false>
|
|
{
|
|
typedef Type type;
|
|
};
|
|
|
|
template <class Type>
|
|
struct get_difference_type<Type, true, true>
|
|
{
|
|
typedef typename Type::difference_type type;
|
|
};
|
|
|
|
//--------------------------------------------------------------------------
|
|
template<class Type>
|
|
struct difference_type_of
|
|
{
|
|
typedef typename
|
|
get_difference_type< Type
|
|
, has_difference<Type>::value
|
|
, has_difference_type<Type>::value
|
|
>::type type;
|
|
};
|
|
|
|
}} // namespace boost icl
|
|
|
|
#endif
|
|
|
|
|