1
2// (C) Copyright John Maddock 2005.
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
10#ifndef BOOST_TT_IS_SIGNED_HPP_INCLUDED
11#define BOOST_TT_IS_SIGNED_HPP_INCLUDED
12
13#include <boost/type_traits/is_integral.hpp>
14#include <boost/type_traits/remove_cv.hpp>
15#include <boost/type_traits/is_enum.hpp>
16#include <climits>
17
18namespace boost {
19
20#if !defined( __CODEGEARC__ )
21
22#if !(defined(BOOST_MSVC) && BOOST_MSVC <= 1310) && \
23 !(defined(__EDG_VERSION__) && __EDG_VERSION__ <= 238) &&\
24 !defined(BOOST_NO_INCLASS_MEMBER_INITIALIZATION)
25
26namespace detail{
27
28template <class T>
29struct is_signed_values
30{
31 //
32 // Note that we cannot use BOOST_STATIC_CONSTANT here, using enum's
33 // rather than "real" static constants simply doesn't work or give
34 // the correct answer.
35 //
36 typedef typename remove_cv<T>::type no_cv_t;
37 static const no_cv_t minus_one = (static_cast<no_cv_t>(-1));
38 static const no_cv_t zero = (static_cast<no_cv_t>(0));
39};
40
41template <class T>
42struct is_signed_helper
43{
44 typedef typename remove_cv<T>::type no_cv_t;
45 BOOST_STATIC_CONSTANT(bool, value = (!(::boost::detail::is_signed_values<T>::minus_one > boost::detail::is_signed_values<T>::zero)));
46};
47
48template <bool integral_type>
49struct is_signed_select_helper
50{
51 template <class T>
52 struct rebind
53 {
54 typedef is_signed_helper<T> type;
55 };
56};
57
58template <>
59struct is_signed_select_helper<false>
60{
61 template <class T>
62 struct rebind
63 {
64 typedef false_type type;
65 };
66};
67
68template <class T>
69struct is_signed_impl
70{
71 typedef ::boost::detail::is_signed_select_helper< ::boost::is_integral<T>::value || ::boost::is_enum<T>::value> selector;
72 typedef typename selector::template rebind<T> binder;
73 typedef typename binder::type type;
74 BOOST_STATIC_CONSTANT(bool, value = type::value);
75};
76
77}
78
79template <class T> struct is_signed : public integral_constant<bool, boost::detail::is_signed_impl<T>::value> {};
80
81#else
82
83template <class T> struct is_signed : public false_type{};
84
85#endif
86
87#else //defined( __CODEGEARC__ )
88 template <class T> struct is_signed : public integral_constant<bool, __is_signed(T)>{};
89#endif
90
91template <> struct is_signed<signed char> : public true_type{};
92template <> struct is_signed<const signed char> : public true_type{};
93template <> struct is_signed<volatile signed char> : public true_type{};
94template <> struct is_signed<const volatile signed char> : public true_type{};
95template <> struct is_signed<short> : public true_type{};
96template <> struct is_signed<const short> : public true_type{};
97template <> struct is_signed<volatile short> : public true_type{};
98template <> struct is_signed<const volatile short> : public true_type{};
99template <> struct is_signed<int> : public true_type{};
100template <> struct is_signed<const int> : public true_type{};
101template <> struct is_signed<volatile int> : public true_type{};
102template <> struct is_signed<const volatile int> : public true_type{};
103template <> struct is_signed<long> : public true_type{};
104template <> struct is_signed<const long> : public true_type{};
105template <> struct is_signed<volatile long> : public true_type{};
106template <> struct is_signed<const volatile long> : public true_type{};
107
108template <> struct is_signed<unsigned char> : public false_type{};
109template <> struct is_signed<const unsigned char> : public false_type{};
110template <> struct is_signed<volatile unsigned char> : public false_type{};
111template <> struct is_signed<const volatile unsigned char> : public false_type{};
112template <> struct is_signed<unsigned short> : public false_type{};
113template <> struct is_signed<const unsigned short> : public false_type{};
114template <> struct is_signed<volatile unsigned short> : public false_type{};
115template <> struct is_signed<const volatile unsigned short> : public false_type{};
116template <> struct is_signed<unsigned int> : public false_type{};
117template <> struct is_signed<const unsigned int> : public false_type{};
118template <> struct is_signed<volatile unsigned int> : public false_type{};
119template <> struct is_signed<const volatile unsigned int> : public false_type{};
120template <> struct is_signed<unsigned long> : public false_type{};
121template <> struct is_signed<const unsigned long> : public false_type{};
122template <> struct is_signed<volatile unsigned long> : public false_type{};
123template <> struct is_signed<const volatile unsigned long> : public false_type{};
124#ifdef BOOST_HAS_LONG_LONG
125template <> struct is_signed< ::boost::long_long_type> : public true_type{};
126template <> struct is_signed<const ::boost::long_long_type> : public true_type{};
127template <> struct is_signed<volatile ::boost::long_long_type> : public true_type{};
128template <> struct is_signed<const volatile ::boost::long_long_type> : public true_type{};
129
130template <> struct is_signed< ::boost::ulong_long_type> : public false_type{};
131template <> struct is_signed<const ::boost::ulong_long_type> : public false_type{};
132template <> struct is_signed<volatile ::boost::ulong_long_type> : public false_type{};
133template <> struct is_signed<const volatile ::boost::ulong_long_type> : public false_type{};
134#endif
135#if defined(CHAR_MIN)
136#if CHAR_MIN != 0
137template <> struct is_signed<char> : public true_type{};
138template <> struct is_signed<const char> : public true_type{};
139template <> struct is_signed<volatile char> : public true_type{};
140template <> struct is_signed<const volatile char> : public true_type{};
141#else
142template <> struct is_signed<char> : public false_type{};
143template <> struct is_signed<const char> : public false_type{};
144template <> struct is_signed<volatile char> : public false_type{};
145template <> struct is_signed<const volatile char> : public false_type{};
146#endif
147#endif
148#if defined(WCHAR_MIN) && !defined(BOOST_NO_INTRINSIC_WCHAR_T)
149#if WCHAR_MIN != 0
150template <> struct is_signed<wchar_t> : public true_type{};
151template <> struct is_signed<const wchar_t> : public true_type{};
152template <> struct is_signed<volatile wchar_t> : public true_type{};
153template <> struct is_signed<const volatile wchar_t> : public true_type{};
154#else
155template <> struct is_signed<wchar_t> : public false_type{};
156template <> struct is_signed<const wchar_t> : public false_type{};
157template <> struct is_signed<volatile wchar_t> : public false_type{};
158template <> struct is_signed<const volatile wchar_t> : public false_type{};
159#endif
160#endif
161} // namespace boost
162
163#endif // BOOST_TT_IS_MEMBER_FUNCTION_POINTER_HPP_INCLUDED
164

source code of boost/boost/type_traits/is_signed.hpp