// Copyright 2005 Alexander Nasonov.

// 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)

#ifndef FILE_boost_type_traits_integral_promotion_hpp_INCLUDED

#define FILE_boost_type_traits_integral_promotion_hpp_INCLUDED

#include <boost/config.hpp>

#include <boost/mpl/eval_if.hpp>

#include <boost/mpl/identity.hpp>

#include <boost/type_traits/integral_constant.hpp>

#include <boost/type_traits/is_const.hpp>

#include <boost/type_traits/is_enum.hpp>

#include <boost/type_traits/is_volatile.hpp>

#include <boost/type_traits/remove_cv.hpp>

// Should be the last #include

#include <boost/type_traits/detail/type_trait_def.hpp>

namespace boost {

namespace type_traits { namespace detail {

// 4.5/2

template <class T> struct need_promotion : boost::is_enum<T> {};

// 4.5/1

template<> struct need_promotion<char              > : true_type {};

template<> struct need_promotion<signed char       > : true_type {};

template<> struct need_promotion<unsigned char     > : true_type {};

template<> struct need_promotion<signed short int  > : true_type {};

template<> struct need_promotion<unsigned short int> : true_type {};

// Specializations for non-standard types.

// Type is promoted if it's smaller then int.

#define BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(T) \

    template<> struct need_promotion<T>          \

        : integral_constant<bool, (sizeof(T) < sizeof(int))> {};

// Same set of integral types as in boost/type_traits/is_integral.hpp.

// Please, keep in sync.

#if (defined(BOOST_MSVC) && (BOOST_MSVC < 1300)) \

    || (defined(BOOST_INTEL_CXX_VERSION) && defined(_MSC_VER) && (BOOST_INTEL_CXX_VERSION <= 600)) \

    || (defined(__BORLANDC__) && (__BORLANDC__ == 0x600) && (_MSC_VER < 1300))

// TODO: common macro for this #if. Or better yet, PP SEQ of non-standard types.

BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(__int8          )

BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(unsigned __int8 )

BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(__int16         )

BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(unsigned __int16)

BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(__int32         )

BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(unsigned __int32)

#ifdef __BORLANDC__

BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(unsigned __int64)

BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(         __int64)

#endif

#endif

#if defined(BOOST_HAS_LONG_LONG)

BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(boost::ulong_long_type)

BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(boost::long_long_type )

#elif defined(BOOST_HAS_MS_INT64)

BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(unsigned __int64)

BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(         __int64)

#endif

#undef BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE

#ifndef BOOST_NO_INTRINSIC_WCHAR_T

// 4.5/2

template<> struct need_promotion<wchar_t> : true_type {};

#endif

// 4.5/3 (integral bit-field) is not supported.

// 4.5/4

template<> struct need_promotion<bool> : true_type {};

// Get promoted type by index and cv qualifiers.

template<int Index, int IsConst, int IsVolatile> struct promote_from_index;

#define BOOST_TT_AUX_PROMOTE_FROM_INDEX(N,T)                                   \

    template<> struct promote_from_index<N,0,0> { typedef T type; };           \

    template<> struct promote_from_index<N,0,1> { typedef T volatile type; };  \

    template<> struct promote_from_index<N,1,0> { typedef T const type; };     \

    template<> struct promote_from_index<N,1,1> { typedef T const volatile type; };

BOOST_TT_AUX_PROMOTE_FROM_INDEX(1, int          )

BOOST_TT_AUX_PROMOTE_FROM_INDEX(2, unsigned int )

BOOST_TT_AUX_PROMOTE_FROM_INDEX(3, long         )

BOOST_TT_AUX_PROMOTE_FROM_INDEX(4, unsigned long)

// WARNING: integral promotions to non-standard types

// long long and __int64 are not defined by the standard.

// Additional specialisations and overloads shouldn't

// introduce ambiguity, though.

#if defined(BOOST_HAS_LONG_LONG)

BOOST_TT_AUX_PROMOTE_FROM_INDEX(5, boost::long_long_type )

BOOST_TT_AUX_PROMOTE_FROM_INDEX(6, boost::ulong_long_type)

#elif defined(BOOST_HAS_MS_INT64)

BOOST_TT_AUX_PROMOTE_FROM_INDEX(7, __int64         )

BOOST_TT_AUX_PROMOTE_FROM_INDEX(8, unsigned __int64)

#endif

#undef BOOST_TT_AUX_PROMOTE_FROM_INDEX

// Define BOOST_TT_AUX_PROMOTED_INDEX_TESTER:

#if !defined(BOOST_MSVC)

template<int N>

struct sized_type_for_promotion

{

    typedef char (&type)[N];

};

#define BOOST_TT_AUX_PROMOTED_INDEX_TESTER(I,T) \

    sized_type_for_promotion<I>::type promoted_index_tester(T);

#else

#define BOOST_TT_AUX_PROMOTED_INDEX_TESTER(I,T) \

    char (&promoted_index_tester(T))[I];

#endif

BOOST_TT_AUX_PROMOTED_INDEX_TESTER(1, int          )

BOOST_TT_AUX_PROMOTED_INDEX_TESTER(2, unsigned int )

BOOST_TT_AUX_PROMOTED_INDEX_TESTER(3, long         )

BOOST_TT_AUX_PROMOTED_INDEX_TESTER(4, unsigned long)

#if defined(BOOST_HAS_LONG_LONG)

BOOST_TT_AUX_PROMOTED_INDEX_TESTER(5, boost::long_long_type )

BOOST_TT_AUX_PROMOTED_INDEX_TESTER(6, boost::ulong_long_type)

#elif defined(BOOST_HAS_MS_INT64)

BOOST_TT_AUX_PROMOTED_INDEX_TESTER(7, __int64         )

BOOST_TT_AUX_PROMOTED_INDEX_TESTER(8, unsigned __int64)

#endif

#undef BOOST_TT_AUX_PROMOTED_INDEX_TESTER

// Get an index of promoted type for type T.

// Precondition: need_promotion<T>

template<class T>

struct promoted_index

{

    static T testee; // undefined

    BOOST_STATIC_CONSTANT(int, value = sizeof(promoted_index_tester(+testee)) );

    // Unary plus promotes testee                    LOOK HERE ---> ^

};

template<class T>

struct integral_promotion_impl

{

    typedef BOOST_DEDUCED_TYPENAME promote_from_index<

        (boost::type_traits::detail::promoted_index<T>::value)

      , (boost::is_const<T>::value)

      , (boost::is_volatile<T>::value)

      >::type type;

};

template<class T>

struct integral_promotion

  : boost::mpl::eval_if<

        need_promotion<BOOST_DEDUCED_TYPENAME remove_cv<T>::type>

      , integral_promotion_impl<T>

      , boost::mpl::identity<T>

      >

{

};

} }

BOOST_TT_AUX_TYPE_TRAIT_DEF1(

      integral_promotion

    , T

    , BOOST_DEDUCED_TYPENAME

        boost::type_traits::detail::integral_promotion<T>::type

    )

}

#include <boost/type_traits/detail/type_trait_undef.hpp>

#endif // #ifndef FILE_boost_type_traits_integral_promotion_hpp_INCLUDED