1// Copyright 2005 Alexander Nasonov.
2// Distributed under the Boost Software License, Version 1.0. (See
3// accompanying file LICENSE_1_0.txt or copy at
4// http://www.boost.org/LICENSE_1_0.txt)
5
6#ifndef FILE_boost_type_traits_integral_promotion_hpp_INCLUDED
7#define FILE_boost_type_traits_integral_promotion_hpp_INCLUDED
8
9#include <boost/config.hpp>
10
11#include <boost/mpl/eval_if.hpp>
12#include <boost/mpl/identity.hpp>
13#include <boost/type_traits/integral_constant.hpp>
14#include <boost/type_traits/is_const.hpp>
15#include <boost/type_traits/is_enum.hpp>
16#include <boost/type_traits/is_volatile.hpp>
17#include <boost/type_traits/remove_cv.hpp>
18
19// Should be the last #include
20#include <boost/type_traits/detail/type_trait_def.hpp>
21
22namespace boost {
23
24namespace type_traits { namespace detail {
25
26// 4.5/2
27template <class T> struct need_promotion : public boost::is_enum<T> {};
28
29// 4.5/1
30template<> struct need_promotion<char > : public true_type {};
31template<> struct need_promotion<signed char > : public true_type {};
32template<> struct need_promotion<unsigned char > : public true_type {};
33template<> struct need_promotion<signed short int > : public true_type {};
34template<> struct need_promotion<unsigned short int> : public true_type {};
35
36
37// Specializations for non-standard types.
38// Type is promoted if it's smaller then int.
39
40#define BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(T) \
41 template<> struct need_promotion<T> \
42 : public integral_constant<bool, (sizeof(T) < sizeof(int))> {};
43
44// Same set of integral types as in boost/type_traits/is_integral.hpp.
45// Please, keep in sync.
46#if (defined(BOOST_INTEL_CXX_VERSION) && defined(_MSC_VER) && (BOOST_INTEL_CXX_VERSION <= 600)) \
47 || (defined(__BORLANDC__) && (__BORLANDC__ == 0x600) && (_MSC_VER < 1300))
48// TODO: common macro for this #if. Or better yet, PP SEQ of non-standard types.
49BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(__int8 )
50BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(unsigned __int8 )
51BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(__int16 )
52BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(unsigned __int16)
53BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(__int32 )
54BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(unsigned __int32)
55#ifdef __BORLANDC__
56BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(unsigned __int64)
57BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE( __int64)
58#endif
59#endif
60
61#if defined(BOOST_HAS_LONG_LONG)
62BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(boost::ulong_long_type)
63BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(boost::long_long_type )
64#elif defined(BOOST_HAS_MS_INT64)
65BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE(unsigned __int64)
66BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE( __int64)
67#endif
68
69#undef BOOST_TT_AUX_PROMOTE_NONSTANDARD_TYPE
70
71
72#ifndef BOOST_NO_INTRINSIC_WCHAR_T
73// 4.5/2
74template<> struct need_promotion<wchar_t> : public true_type {};
75#endif
76
77// 4.5/3 (integral bit-field) is not supported.
78
79// 4.5/4
80template<> struct need_promotion<bool> : public true_type {};
81
82
83// Get promoted type by index and cv qualifiers.
84
85template<int Index, int IsConst, int IsVolatile> struct promote_from_index;
86
87#define BOOST_TT_AUX_PROMOTE_FROM_INDEX(N,T) \
88 template<> struct promote_from_index<N,0,0> { typedef T type; }; \
89 template<> struct promote_from_index<N,0,1> { typedef T volatile type; }; \
90 template<> struct promote_from_index<N,1,0> { typedef T const type; }; \
91 template<> struct promote_from_index<N,1,1> { typedef T const volatile type; };
92
93
94BOOST_TT_AUX_PROMOTE_FROM_INDEX(1, int )
95BOOST_TT_AUX_PROMOTE_FROM_INDEX(2, unsigned int )
96BOOST_TT_AUX_PROMOTE_FROM_INDEX(3, long )
97BOOST_TT_AUX_PROMOTE_FROM_INDEX(4, unsigned long)
98
99
100// WARNING: integral promotions to non-standard types
101// long long and __int64 are not defined by the standard.
102// Additional specialisations and overloads shouldn't
103// introduce ambiguity, though.
104
105#if defined(BOOST_HAS_LONG_LONG)
106BOOST_TT_AUX_PROMOTE_FROM_INDEX(5, boost::long_long_type )
107BOOST_TT_AUX_PROMOTE_FROM_INDEX(6, boost::ulong_long_type)
108#elif defined(BOOST_HAS_MS_INT64)
109BOOST_TT_AUX_PROMOTE_FROM_INDEX(7, __int64 )
110BOOST_TT_AUX_PROMOTE_FROM_INDEX(8, unsigned __int64)
111#endif
112
113#undef BOOST_TT_AUX_PROMOTE_FROM_INDEX
114
115
116// Define BOOST_TT_AUX_PROMOTED_INDEX_TESTER:
117#if !defined(BOOST_MSVC)
118
119template<int N>
120struct sized_type_for_promotion
121{
122 typedef char (&type)[N];
123};
124
125#define BOOST_TT_AUX_PROMOTED_INDEX_TESTER(I,T) \
126 sized_type_for_promotion<I>::type promoted_index_tester(T);
127
128#else
129
130#define BOOST_TT_AUX_PROMOTED_INDEX_TESTER(I,T) \
131 char (&promoted_index_tester(T))[I];
132
133#endif
134
135BOOST_TT_AUX_PROMOTED_INDEX_TESTER(1, int )
136BOOST_TT_AUX_PROMOTED_INDEX_TESTER(2, unsigned int )
137BOOST_TT_AUX_PROMOTED_INDEX_TESTER(3, long )
138BOOST_TT_AUX_PROMOTED_INDEX_TESTER(4, unsigned long)
139
140#if defined(BOOST_HAS_LONG_LONG)
141BOOST_TT_AUX_PROMOTED_INDEX_TESTER(5, boost::long_long_type )
142BOOST_TT_AUX_PROMOTED_INDEX_TESTER(6, boost::ulong_long_type)
143#elif defined(BOOST_HAS_MS_INT64)
144BOOST_TT_AUX_PROMOTED_INDEX_TESTER(7, __int64 )
145BOOST_TT_AUX_PROMOTED_INDEX_TESTER(8, unsigned __int64)
146#endif
147
148#undef BOOST_TT_AUX_PROMOTED_INDEX_TESTER
149
150
151// Get an index of promoted type for type T.
152// Precondition: need_promotion<T>
153template<class T>
154struct promoted_index
155{
156 static T testee; // undefined
157 BOOST_STATIC_CONSTANT(int, value = sizeof(promoted_index_tester(+testee)) );
158 // Unary plus promotes testee LOOK HERE ---> ^
159};
160
161template<class T>
162struct integral_promotion_impl
163{
164 typedef BOOST_DEDUCED_TYPENAME promote_from_index<
165 (boost::type_traits::detail::promoted_index<T>::value)
166 , (boost::is_const<T>::value)
167 , (boost::is_volatile<T>::value)
168 >::type type;
169};
170
171template<class T>
172struct integral_promotion
173 : public boost::mpl::eval_if<
174 need_promotion<BOOST_DEDUCED_TYPENAME remove_cv<T>::type>
175 , integral_promotion_impl<T>
176 , boost::mpl::identity<T>
177 >
178{
179};
180
181} }
182
183BOOST_TT_AUX_TYPE_TRAIT_DEF1(
184 integral_promotion
185 , T
186 , BOOST_DEDUCED_TYPENAME
187 boost::type_traits::detail::integral_promotion<T>::type
188 )
189}
190
191#include <boost/type_traits/detail/type_trait_undef.hpp>
192
193#endif // #ifndef FILE_boost_type_traits_integral_promotion_hpp_INCLUDED
194
195