boost/type_traits/is_pod.hpp

   1
   2 //  (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000.
   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_IS_POD_HPP_INCLUDED
  10 #define BOOST_TT_IS_POD_HPP_INCLUDED
  11
  12 #include <boost/type_traits/config.hpp>
  13 #include <boost/type_traits/is_void.hpp>
  14 #include <boost/type_traits/is_scalar.hpp>
  15 #include <boost/type_traits/detail/ice_or.hpp>
  16 #include <boost/type_traits/intrinsics.hpp>
  17
  18 #include <cstddef>
  19
  20 // should be the last #include
  21 #include <boost/type_traits/detail/bool_trait_def.hpp>
  22
  23 #ifndef BOOST_IS_POD
  24 #define BOOST_INTERNAL_IS_POD(T) false
  25 #else
  26 #define BOOST_INTERNAL_IS_POD(T) BOOST_IS_POD(T)
  27 #endif
  28
  29 namespace boost {
  30
  31 // forward declaration, needed by 'is_pod_array_helper' template below
  32 template< typename T > struct is_POD;
  33
  34 namespace detail {
  35
  36 #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
  37
  38 template <typename T> struct is_pod_impl
  39 {
  40     BOOST_STATIC_CONSTANT(
  41         bool, value =
  42         (::boost::type_traits::ice_or<
  43             ::boost::is_scalar<T>::value,
  44             ::boost::is_void<T>::value,
  45             BOOST_INTERNAL_IS_POD(T)
  46          >::value));
  47 };
  48
  49 #if !defined(BOOST_NO_ARRAY_TYPE_SPECIALIZATIONS)
  50 template <typename T, std::size_t sz>
  51 struct is_pod_impl<T[sz]>
  52     : public is_pod_impl<T>
  53 {
  54 };
  55 #endif
  56
  57 #else
  58
  59 template <bool is_array = false>
  60 struct is_pod_helper
  61 {
  62     template <typename T> struct result_
  63     {
  64         BOOST_STATIC_CONSTANT(
  65             bool, value =
  66             (::boost::type_traits::ice_or<
  67                 ::boost::is_scalar<T>::value,
  68                 ::boost::is_void<T>::value,
  69                 BOOST_INTERNAL_IS_POD(T)
  70             >::value));
  71     };
  72 };
  73
  74 template <bool b>
  75 struct bool_to_yes_no_type
  76 {
  77     typedef ::boost::type_traits::no_type type;
  78 };
  79
  80 template <>
  81 struct bool_to_yes_no_type<true>
  82 {
  83     typedef ::boost::type_traits::yes_type type;
  84 };
  85
  86 template <typename ArrayType>
  87 struct is_pod_array_helper
  88 {
  89     enum { is_pod = ::boost::is_POD<ArrayType>::value }; // MSVC workaround
  90     typedef typename bool_to_yes_no_type<is_pod>::type type;
  91     type instance() const;
  92 };
  93
  94 template <typename T>
  95 is_pod_array_helper<T> is_POD_array(T*);
  96
  97 template <>
  98 struct is_pod_helper<true>
  99 {
 100     template <typename T> struct result_
 101     {
 102         static T& help();
 103         BOOST_STATIC_CONSTANT(bool, value =
 104             sizeof(is_POD_array(help()).instance()) == sizeof(::boost::type_traits::yes_type)
 105             );
 106     };
 107 };
 108
 109
 110 template <typename T> struct is_pod_impl
 111 {
 112    BOOST_STATIC_CONSTANT(
 113        bool, value = (
 114            ::boost::detail::is_pod_helper<
 115               ::boost::is_array<T>::value
 116            >::template result_<T>::value
 117            )
 118        );
 119 };
 120
 121 #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
 122
 123 // the following help compilers without partial specialization support:
 124 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,void,true)
 125
 126 #ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS
 127 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,void const,true)
 128 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,void volatile,true)
 129 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,void const volatile,true)
 130 #endif
 131
 132 } // namespace detail
 133
 134 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_pod,T,::boost::detail::is_pod_impl<T>::value)
 135 // is_POD is the old depricated name for this trait, do not use this as it may
 136 // be removed in future without warning!!
 137 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_POD,T,::boost::is_pod<T>::value)
 138
 139 } // namespace boost
 140
 141 #include <boost/type_traits/detail/bool_trait_undef.hpp>
 142
 143 #undef BOOST_INTERNAL_IS_POD
 144
 145 #endif // BOOST_TT_IS_POD_HPP_INCLUDED