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 
25 namespace boost {
26 
27 template <class T>
28 struct make_signed
29 {
30 private:
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;
119 public:
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