is_signed.hpp 6.5 KB

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  1. // (C) Copyright John Maddock 2005.
  2. // Use, modification and distribution are subject to the Boost Software License,
  3. // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  4. // http://www.boost.org/LICENSE_1_0.txt).
  5. //
  6. // See http://www.boost.org/libs/type_traits for most recent version including documentation.
  7. #ifndef BOOST_TT_IS_SIGNED_HPP_INCLUDED
  8. #define BOOST_TT_IS_SIGNED_HPP_INCLUDED
  9. #include <boost/type_traits/is_integral.hpp>
  10. #include <boost/type_traits/remove_cv.hpp>
  11. #include <boost/type_traits/is_enum.hpp>
  12. #include <climits>
  13. namespace boost {
  14. #if !defined( __CODEGEARC__ )
  15. #if !(defined(BOOST_MSVC) && BOOST_MSVC <= 1310) && \
  16. !(defined(__EDG_VERSION__) && __EDG_VERSION__ <= 238) &&\
  17. !defined(BOOST_NO_INCLASS_MEMBER_INITIALIZATION)
  18. namespace detail{
  19. template <class T>
  20. struct is_signed_values
  21. {
  22. //
  23. // Note that we cannot use BOOST_STATIC_CONSTANT here, using enum's
  24. // rather than "real" static constants simply doesn't work or give
  25. // the correct answer.
  26. //
  27. typedef typename remove_cv<T>::type no_cv_t;
  28. static const no_cv_t minus_one = (static_cast<no_cv_t>(-1));
  29. static const no_cv_t zero = (static_cast<no_cv_t>(0));
  30. };
  31. template <class T>
  32. struct is_signed_helper
  33. {
  34. typedef typename remove_cv<T>::type no_cv_t;
  35. BOOST_STATIC_CONSTANT(bool, value = (!(::boost::detail::is_signed_values<T>::minus_one > boost::detail::is_signed_values<T>::zero)));
  36. };
  37. template <bool integral_type>
  38. struct is_signed_select_helper
  39. {
  40. template <class T>
  41. struct rebind
  42. {
  43. typedef is_signed_helper<T> type;
  44. };
  45. };
  46. template <>
  47. struct is_signed_select_helper<false>
  48. {
  49. template <class T>
  50. struct rebind
  51. {
  52. typedef false_type type;
  53. };
  54. };
  55. template <class T>
  56. struct is_signed_impl
  57. {
  58. typedef ::boost::detail::is_signed_select_helper< ::boost::is_integral<T>::value || ::boost::is_enum<T>::value> selector;
  59. typedef typename selector::template rebind<T> binder;
  60. typedef typename binder::type type;
  61. BOOST_STATIC_CONSTANT(bool, value = type::value);
  62. };
  63. }
  64. template <class T> struct is_signed : public integral_constant<bool, boost::detail::is_signed_impl<T>::value> {};
  65. #else
  66. template <class T> struct is_signed : public false_type{};
  67. #endif
  68. #else //defined( __CODEGEARC__ )
  69. template <class T> struct is_signed : public integral_constant<bool, __is_signed(T)>{};
  70. #endif
  71. template <> struct is_signed<signed char> : public true_type{};
  72. template <> struct is_signed<const signed char> : public true_type{};
  73. template <> struct is_signed<volatile signed char> : public true_type{};
  74. template <> struct is_signed<const volatile signed char> : public true_type{};
  75. template <> struct is_signed<short> : public true_type{};
  76. template <> struct is_signed<const short> : public true_type{};
  77. template <> struct is_signed<volatile short> : public true_type{};
  78. template <> struct is_signed<const volatile short> : public true_type{};
  79. template <> struct is_signed<int> : public true_type{};
  80. template <> struct is_signed<const int> : public true_type{};
  81. template <> struct is_signed<volatile int> : public true_type{};
  82. template <> struct is_signed<const volatile int> : public true_type{};
  83. template <> struct is_signed<long> : public true_type{};
  84. template <> struct is_signed<const long> : public true_type{};
  85. template <> struct is_signed<volatile long> : public true_type{};
  86. template <> struct is_signed<const volatile long> : public true_type{};
  87. template <> struct is_signed<unsigned char> : public false_type{};
  88. template <> struct is_signed<const unsigned char> : public false_type{};
  89. template <> struct is_signed<volatile unsigned char> : public false_type{};
  90. template <> struct is_signed<const volatile unsigned char> : public false_type{};
  91. template <> struct is_signed<unsigned short> : public false_type{};
  92. template <> struct is_signed<const unsigned short> : public false_type{};
  93. template <> struct is_signed<volatile unsigned short> : public false_type{};
  94. template <> struct is_signed<const volatile unsigned short> : public false_type{};
  95. template <> struct is_signed<unsigned int> : public false_type{};
  96. template <> struct is_signed<const unsigned int> : public false_type{};
  97. template <> struct is_signed<volatile unsigned int> : public false_type{};
  98. template <> struct is_signed<const volatile unsigned int> : public false_type{};
  99. template <> struct is_signed<unsigned long> : public false_type{};
  100. template <> struct is_signed<const unsigned long> : public false_type{};
  101. template <> struct is_signed<volatile unsigned long> : public false_type{};
  102. template <> struct is_signed<const volatile unsigned long> : public false_type{};
  103. #ifdef BOOST_HAS_LONG_LONG
  104. template <> struct is_signed< ::boost::long_long_type> : public true_type{};
  105. template <> struct is_signed<const ::boost::long_long_type> : public true_type{};
  106. template <> struct is_signed<volatile ::boost::long_long_type> : public true_type{};
  107. template <> struct is_signed<const volatile ::boost::long_long_type> : public true_type{};
  108. template <> struct is_signed< ::boost::ulong_long_type> : public false_type{};
  109. template <> struct is_signed<const ::boost::ulong_long_type> : public false_type{};
  110. template <> struct is_signed<volatile ::boost::ulong_long_type> : public false_type{};
  111. template <> struct is_signed<const volatile ::boost::ulong_long_type> : public false_type{};
  112. #endif
  113. #if defined(CHAR_MIN)
  114. #if CHAR_MIN != 0
  115. template <> struct is_signed<char> : public true_type{};
  116. template <> struct is_signed<const char> : public true_type{};
  117. template <> struct is_signed<volatile char> : public true_type{};
  118. template <> struct is_signed<const volatile char> : public true_type{};
  119. #else
  120. template <> struct is_signed<char> : public false_type{};
  121. template <> struct is_signed<const char> : public false_type{};
  122. template <> struct is_signed<volatile char> : public false_type{};
  123. template <> struct is_signed<const volatile char> : public false_type{};
  124. #endif
  125. #endif
  126. #if defined(WCHAR_MIN) && !defined(BOOST_NO_INTRINSIC_WCHAR_T)
  127. #if WCHAR_MIN != 0
  128. template <> struct is_signed<wchar_t> : public true_type{};
  129. template <> struct is_signed<const wchar_t> : public true_type{};
  130. template <> struct is_signed<volatile wchar_t> : public true_type{};
  131. template <> struct is_signed<const volatile wchar_t> : public true_type{};
  132. #else
  133. template <> struct is_signed<wchar_t> : public false_type{};
  134. template <> struct is_signed<const wchar_t> : public false_type{};
  135. template <> struct is_signed<volatile wchar_t> : public false_type{};
  136. template <> struct is_signed<const volatile wchar_t> : public false_type{};
  137. #endif
  138. #endif
  139. } // namespace boost
  140. #endif // BOOST_TT_IS_MEMBER_FUNCTION_POINTER_HPP_INCLUDED