ceph/src/boost/boost/type_traits/is_class.hpp

   1 //  (C) Copyright Dave Abrahams, Steve Cleary, Beman Dawes, Howard
   2 //  Hinnant & John Maddock 2000-2003.
   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_CLASS_HPP_INCLUDED
  11 #define BOOST_TT_IS_CLASS_HPP_INCLUDED
  12
  13 #include <boost/type_traits/detail/config.hpp>
  14 #include <boost/type_traits/intrinsics.hpp>
  15 #include <boost/type_traits/integral_constant.hpp>
  16 #ifndef BOOST_IS_CLASS
  17 #   include <boost/type_traits/is_union.hpp>
  18
  19 #ifdef BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION
  20 #   include <boost/type_traits/detail/yes_no_type.hpp>
  21 #else
  22 #   include <boost/type_traits/is_scalar.hpp>
  23 #   include <boost/type_traits/is_array.hpp>
  24 #   include <boost/type_traits/is_reference.hpp>
  25 #   include <boost/type_traits/is_void.hpp>
  26 #   include <boost/type_traits/is_function.hpp>
  27 #endif
  28
  29 #endif // BOOST_IS_CLASS
  30
  31 namespace boost {
  32
  33 namespace detail {
  34
  35 #ifndef BOOST_IS_CLASS
  36 #ifdef BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION
  37
  38 // This is actually the conforming implementation which works with
  39 // abstract classes.  However, enough compilers have trouble with
  40 // it that most will use the one in
  41 // boost/type_traits/object_traits.hpp. This implementation
  42 // actually works with VC7.0, but other interactions seem to fail
  43 // when we use it.
  44
  45 // is_class<> metafunction due to Paul Mensonides
  46 // (leavings@attbi.com). For more details:
  47 // http://groups.google.com/groups?hl=en&selm=000001c1cc83%24e154d5e0%247772e50c%40c161550a&rnum=1
  48 #if defined(__GNUC__)  && !defined(__EDG_VERSION__)
  49
  50 template <class U> ::boost::type_traits::yes_type is_class_tester(void(U::*)(void));
  51 template <class U> ::boost::type_traits::no_type is_class_tester(...);
  52
  53 template <typename T>
  54 struct is_class_impl
  55 {
  56
  57     BOOST_STATIC_CONSTANT(bool, value =
  58             sizeof(is_class_tester<T>(0)) == sizeof(::boost::type_traits::yes_type)
  59             && ! ::boost::is_union<T>::value
  60         );
  61 };
  62
  63 #else
  64
  65 template <typename T>
  66 struct is_class_impl
  67 {
  68     template <class U> static ::boost::type_traits::yes_type is_class_tester(void(U::*)(void));
  69     template <class U> static ::boost::type_traits::no_type is_class_tester(...);
  70
  71     BOOST_STATIC_CONSTANT(bool, value =
  72             sizeof(is_class_tester<T>(0)) == sizeof(::boost::type_traits::yes_type)
  73             && ! ::boost::is_union<T>::value
  74         );
  75 };
  76
  77 #endif
  78
  79 #else
  80
  81 template <typename T>
  82 struct is_class_impl
  83 {
  84     BOOST_STATIC_CONSTANT(bool, value =
  85         ! ::boost::is_union<T>::value >::value
  86         && ! ::boost::is_scalar<T>::value
  87         && ! ::boost::is_array<T>::value
  88         && ! ::boost::is_reference<T>::value
  89         && ! ::boost::is_void<T>::value
  90         && ! ::boost::is_function<T>::value
  91         );
  92 };
  93
  94 # endif // BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION
  95 # else // BOOST_IS_CLASS
  96 template <typename T>
  97 struct is_class_impl
  98 {
  99     BOOST_STATIC_CONSTANT(bool, value = BOOST_IS_CLASS(T));
 100 };
 101 # endif // BOOST_IS_CLASS
 102
 103 } // namespace detail
 104
 105 template <class T> struct is_class : public integral_constant<bool, ::boost::detail::is_class_impl<T>::value> {};
 106 # ifdef __EDG_VERSION__
 107 template <class T> struct is_class<const T> : public is_class<T>{};
 108 template <class T> struct is_class<const volatile T> : public is_class<T>{};
 109 template <class T> struct is_class<volatile T> : public is_class<T>{};
 110 # endif
 111
 112 } // namespace boost
 113
 114 #endif // BOOST_TT_IS_CLASS_HPP_INCLUDED