boost/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 #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
  46
  47 namespace detail {
  48
  49 template< typename T > struct is_pointer_helper
  50 {
  51     BOOST_STATIC_CONSTANT(bool, value = false);
  52 };
  53
  54 #   define TT_AUX_BOOL_TRAIT_HELPER_PARTIAL_SPEC(helper,sp,result) \
  55 template< typename T > struct helper<sp> \
  56 { \
  57     BOOST_STATIC_CONSTANT(bool, value = result); \
  58 }; \
  59 /**/
  60
  61 TT_AUX_BOOL_TRAIT_HELPER_PARTIAL_SPEC(is_pointer_helper,T*,true)
  62
  63 #   undef TT_AUX_BOOL_TRAIT_HELPER_PARTIAL_SPEC
  64
  65 template< typename T >
  66 struct is_pointer_impl
  67 {
  68 #if BOOST_WORKAROUND(BOOST_MSVC,<=1300)
  69     BOOST_STATIC_CONSTANT(bool, value =
  70         (::boost::type_traits::ice_and<
  71               ::boost::detail::is_pointer_helper<T>::value
  72             , ::boost::type_traits::ice_not<
  73                 ::boost::is_member_pointer<T>::value
  74                 >::value
  75             >::value)
  76         );
  77 #else
  78     BOOST_STATIC_CONSTANT(bool, value =
  79         (::boost::type_traits::ice_and<
  80         ::boost::detail::is_pointer_helper<typename remove_cv<T>::type>::value
  81             , ::boost::type_traits::ice_not<
  82                 ::boost::is_member_pointer<T>::value
  83                 >::value
  84             >::value)
  85         );
  86 #endif
  87 };
  88
  89 } // namespace detail
  90
  91 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_pointer,T,::boost::detail::is_pointer_impl<T>::value)
  92
  93 #if defined(__BORLANDC__) && !defined(__COMO__) && (__BORLANDC__ < 0x600)
  94 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_pointer,T&,false)
  95 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_pointer,T& const,false)
  96 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_pointer,T& volatile,false)
  97 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_pointer,T& const volatile,false)
  98 #endif
  99
 100 #else // no partial template specialization
 101
 102 namespace detail {
 103
 104 struct pointer_helper
 105 {
 106     pointer_helper(const volatile void*);
 107 };
 108
 109 yes_type BOOST_TT_DECL is_pointer_tester(pointer_helper);
 110 no_type BOOST_TT_DECL is_pointer_tester(...);
 111
 112 template <bool>
 113 struct is_pointer_select
 114     : ::boost::type_traits::false_result
 115 {
 116 };
 117
 118 template <>
 119 struct is_pointer_select<false>
 120 {
 121     template <typename T> struct result_
 122     {
 123         static T& make_t();
 124         BOOST_STATIC_CONSTANT(bool, value =
 125                 (::boost::type_traits::ice_or<
 126                     (1 == sizeof(is_pointer_tester(make_t()))),
 127                     (1 == sizeof(type_traits::is_function_ptr_tester(make_t())))
 128                 >::value));
 129     };
 130 };
 131
 132 template <typename T>
 133 struct is_pointer_impl
 134     : is_pointer_select<
 135           ::boost::type_traits::ice_or<
 136               ::boost::is_reference<T>::value
 137             , ::boost::is_array<T>::value
 138             >::value
 139         >::template result_<T>
 140 {
 141 };
 142
 143 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pointer,void,false)
 144 #ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS
 145 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pointer,void const,false)
 146 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pointer,void volatile,false)
 147 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pointer,void const volatile,false)
 148 #endif
 149
 150 } // namespace detail
 151
 152 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_pointer,T,::boost::detail::is_pointer_impl<T>::value)
 153
 154 #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
 155
 156 } // namespace boost
 157
 158 #include <boost/type_traits/detail/bool_trait_undef.hpp>
 159
 160 #endif // BOOST_TT_IS_POINTER_HPP_INCLUDED