1
2// (C) Copyright John Maddock 2007.
3// Use, modification and distribution are subject to the Boost Software License,
4// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
5// http://www.boost.org/LICENSE_1_0.txt).
6//
7// See http://www.boost.org/libs/type_traits for most recent version including documentation.
8
9#ifndef BOOST_TT_MAKE_SIGNED_HPP_INCLUDED
10#define BOOST_TT_MAKE_SIGNED_HPP_INCLUDED
11
12#include <boost/type_traits/conditional.hpp>
13#include <boost/type_traits/is_integral.hpp>
14#include <boost/type_traits/is_signed.hpp>
15#include <boost/type_traits/is_unsigned.hpp>
16#include <boost/type_traits/is_enum.hpp>
17#include <boost/type_traits/is_same.hpp>
18#include <boost/type_traits/remove_cv.hpp>
19#include <boost/type_traits/is_const.hpp>
20#include <boost/type_traits/is_volatile.hpp>
21#include <boost/type_traits/add_const.hpp>
22#include <boost/type_traits/add_volatile.hpp>
23#include <boost/static_assert.hpp>
24
25namespace boost {
26
27template <class T>
28struct make_signed
29{
30private:
31 BOOST_STATIC_ASSERT_MSG(( ::boost::is_integral<T>::value || ::boost::is_enum<T>::value), "The template argument to make_signed must be an integer or enum type.");
32 BOOST_STATIC_ASSERT_MSG(!(::boost::is_same<typename remove_cv<T>::type, bool>::value), "The template argument to make_signed must not be the type bool.");
33
34 typedef typename remove_cv<T>::type t_no_cv;
35 typedef typename conditional<
36 (::boost::is_signed<T>::value
37 && ::boost::is_integral<T>::value
38 && ! ::boost::is_same<t_no_cv, char>::value
39 && ! ::boost::is_same<t_no_cv, wchar_t>::value
40 && ! ::boost::is_same<t_no_cv, bool>::value),
41 T,
42 typename conditional<
43 (::boost::is_integral<T>::value
44 && ! ::boost::is_same<t_no_cv, char>::value
45 && ! ::boost::is_same<t_no_cv, wchar_t>::value
46 && ! ::boost::is_same<t_no_cv, bool>::value),
47 typename conditional<
48 is_same<t_no_cv, unsigned char>::value,
49 signed char,
50 typename conditional<
51 is_same<t_no_cv, unsigned short>::value,
52 signed short,
53 typename conditional<
54 is_same<t_no_cv, unsigned int>::value,
55 int,
56 typename conditional<
57 is_same<t_no_cv, unsigned long>::value,
58 long,
59#if defined(BOOST_HAS_LONG_LONG)
60#ifdef BOOST_HAS_INT128
61 typename conditional<
62 sizeof(t_no_cv) == sizeof(boost::long_long_type),
63 boost::long_long_type,
64 boost::int128_type
65 >::type
66#else
67 boost::long_long_type
68#endif
69#elif defined(BOOST_HAS_MS_INT64)
70 __int64
71#else
72 long
73#endif
74 >::type
75 >::type
76 >::type
77 >::type,
78 // Not a regular integer type:
79 typename conditional<
80 sizeof(t_no_cv) == sizeof(unsigned char),
81 signed char,
82 typename conditional<
83 sizeof(t_no_cv) == sizeof(unsigned short),
84 signed short,
85 typename conditional<
86 sizeof(t_no_cv) == sizeof(unsigned int),
87 int,
88 typename conditional<
89 sizeof(t_no_cv) == sizeof(unsigned long),
90 long,
91#if defined(BOOST_HAS_LONG_LONG)
92#ifdef BOOST_HAS_INT128
93 typename conditional<
94 sizeof(t_no_cv) == sizeof(boost::long_long_type),
95 boost::long_long_type,
96 boost::int128_type
97 >::type
98#else
99 boost::long_long_type
100#endif
101#elif defined(BOOST_HAS_MS_INT64)
102 __int64
103#else
104 long
105#endif
106 >::type
107 >::type
108 >::type
109 >::type
110 >::type
111 >::type base_integer_type;
112
113 // Add back any const qualifier:
114 typedef typename conditional<
115 is_const<T>::value,
116 typename add_const<base_integer_type>::type,
117 base_integer_type
118 >::type const_base_integer_type;
119public:
120 // Add back any volatile qualifier:
121 typedef typename conditional<
122 is_volatile<T>::value,
123 typename add_volatile<const_base_integer_type>::type,
124 const_base_integer_type
125 >::type type;
126};
127
128#if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
129
130 template <class T> using make_signed_t = typename make_signed<T>::type;
131
132#endif
133
134} // namespace boost
135
136#endif // BOOST_TT_ADD_REFERENCE_HPP_INCLUDED
137
138

source code of include/boost/type_traits/make_signed.hpp