boost/type_traits/is_pointer.hpp

   1
   2 //  (C) Copyright Dave Abrahams, Steve Cleary, Beman Dawes,
   3 //      Howard Hinnant and John Maddock 2000.
   4 //  (C) Copyright Mat Marcus, Jesse Jones and Adobe Systems Inc 2001
   5
   6 //  Use, modification and distribution are subject to the Boost Software License,
   7 //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   8 //  http://www.boost.org/LICENSE_1_0.txt).
   9 //
  10 //  See http://www.boost.org/libs/type_traits for most recent version including documentation.
  11
  12 //    Fixed is_pointer, is_reference, is_const, is_volatile, is_same,
  13 //    is_member_pointer based on the Simulated Partial Specialization work
  14 //    of Mat Marcus and Jesse Jones. See  http://opensource.adobe.com or
  15 //    http://groups.yahoo.com/group/boost/message/5441
  16 //    Some workarounds in here use ideas suggested from "Generic<Programming>:
  17 //    Mappings between Types and Values"
  18 //    by Andrei Alexandrescu (see http://www.cuj.com/experts/1810/alexandr.html).
  19
  20
  21 #ifndef BOOST_TT_IS_POINTER_HPP_INCLUDED
  22 #define BOOST_TT_IS_POINTER_HPP_INCLUDED
  23
  24 #include <boost/type_traits/is_member_pointer.hpp>
  25 #include <boost/type_traits/detail/ice_and.hpp>
  26 #include <boost/type_traits/detail/ice_not.hpp>
  27 #include <boost/type_traits/config.hpp>
  28 #if !BOOST_WORKAROUND(BOOST_MSVC,<=1300)
  29 #include <boost/type_traits/remove_cv.hpp>
  30 #endif
  31
  32 #ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
  33 #   include <boost/type_traits/is_reference.hpp>
  34 #   include <boost/type_traits/is_array.hpp>
  35 #   include <boost/type_traits/detail/is_function_ptr_tester.hpp>
  36 #   include <boost/type_traits/detail/false_result.hpp>
  37 #   include <boost/type_traits/detail/ice_or.hpp>
  38 #endif
  39
  40 // should be the last #include
  41 #include <boost/type_traits/detail/bool_trait_def.hpp>
  42
  43 namespace boost {
  44
  45 #if defined( __CODEGEARC__ )
  46 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_pointer,T,__is_pointer(T))
  47 #elif !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
  48
  49 namespace detail {
  50
  51 template< typename T > struct is_pointer_helper
  52 {
  53     BOOST_STATIC_CONSTANT(bool, value = false);
  54 };
  55
  56 #   define TT_AUX_BOOL_TRAIT_HELPER_PARTIAL_SPEC(helper,sp,result) \
  57 template< typename T > struct helper<sp> \
  58 { \
  59     BOOST_STATIC_CONSTANT(bool, value = result); \
  60 }; \
  61 /**/
  62
  63 TT_AUX_BOOL_TRAIT_HELPER_PARTIAL_SPEC(is_pointer_helper,T*,true)
  64
  65 #   undef TT_AUX_BOOL_TRAIT_HELPER_PARTIAL_SPEC
  66
  67 template< typename T >
  68 struct is_pointer_impl
  69 {
  70 #if BOOST_WORKAROUND(BOOST_MSVC,<=1300)
  71     BOOST_STATIC_CONSTANT(bool, value =
  72         (::boost::type_traits::ice_and<
  73               ::boost::detail::is_pointer_helper<T>::value
  74             , ::boost::type_traits::ice_not<
  75                 ::boost::is_member_pointer<T>::value
  76                 >::value
  77             >::value)
  78         );
  79 #else
  80     BOOST_STATIC_CONSTANT(bool, value =
  81         (::boost::type_traits::ice_and<
  82         ::boost::detail::is_pointer_helper<typename remove_cv<T>::type>::value
  83             , ::boost::type_traits::ice_not<
  84                 ::boost::is_member_pointer<T>::value
  85                 >::value
  86             >::value)
  87         );
  88 #endif
  89 };
  90
  91 } // namespace detail
  92
  93 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_pointer,T,::boost::detail::is_pointer_impl<T>::value)
  94
  95 #if defined(__BORLANDC__) && !defined(__COMO__) && (__BORLANDC__ < 0x600)
  96 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_pointer,T&,false)
  97 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_pointer,T& const,false)
  98 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_pointer,T& volatile,false)
  99 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_pointer,T& const volatile,false)
 100 #endif
 101
 102 #else // no partial template specialization
 103
 104 namespace detail {
 105
 106 struct pointer_helper
 107 {
 108     pointer_helper(const volatile void*);
 109 };
 110
 111 yes_type BOOST_TT_DECL is_pointer_tester(pointer_helper);
 112 no_type BOOST_TT_DECL is_pointer_tester(...);
 113
 114 template <bool>
 115 struct is_pointer_select
 116     : public ::boost::type_traits::false_result
 117 {
 118 };
 119
 120 template <>
 121 struct is_pointer_select<false>
 122 {
 123     template <typename T> struct result_
 124     {
 125         static T& make_t();
 126         BOOST_STATIC_CONSTANT(bool, value =
 127                 (::boost::type_traits::ice_or<
 128                     (1 == sizeof(is_pointer_tester(make_t()))),
 129                     (1 == sizeof(type_traits::is_function_ptr_tester(make_t())))
 130                 >::value));
 131     };
 132 };
 133
 134 template <typename T>
 135 struct is_pointer_impl
 136     : public is_pointer_select<
 137           ::boost::type_traits::ice_or<
 138               ::boost::is_reference<T>::value
 139             , ::boost::is_array<T>::value
 140             >::value
 141         >::template result_<T>
 142 {
 143 };
 144
 145 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pointer,void,false)
 146 #ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS
 147 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pointer,void const,false)
 148 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pointer,void volatile,false)
 149 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pointer,void const volatile,false)
 150 #endif
 151
 152 } // namespace detail
 153
 154 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_pointer,T,::boost::detail::is_pointer_impl<T>::value)
 155
 156 #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
 157
 158 } // namespace boost
 159
 160 #include <boost/type_traits/detail/bool_trait_undef.hpp>
 161
 162 #endif // BOOST_TT_IS_POINTER_HPP_INCLUDED