ceph/src/boost/boost/ptr_container/nullable.hpp

   1 //
   2 // Boost.Pointer Container
   3 //
   4 //  Copyright Thorsten Ottosen 2003-2005. Use, modification and
   5 //  distribution is subject to the Boost Software License, Version
   6 //  1.0. (See accompanying file LICENSE_1_0.txt or copy at
   7 //  http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9 // For more information, see http://www.boost.org/libs/ptr_container/
  10 //
  11
  12
  13 #ifndef BOOST_INDIRECT_CONTAINER_NULLABLE_HPP
  14 #define BOOST_INDIRECT_CONTAINER_NULLABLE_HPP
  15
  16 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  17 # pragma once
  18 #endif
  19
  20 #include <boost/type_traits/detail/yes_no_type.hpp>
  21 #include <boost/type_traits/is_const.hpp>
  22 #include <boost/mpl/eval_if.hpp>
  23 #include <boost/mpl/identity.hpp>
  24 #include <boost/config.hpp>
  25
  26 namespace boost
  27 {
  28
  29     template< class T >
  30     struct nullable
  31     {
  32         typedef T type;
  33     };
  34
  35     namespace ptr_container_detail
  36     {
  37         template< class T >
  38         type_traits::yes_type is_nullable( const nullable<T>* );
  39
  40         type_traits::no_type is_nullable( ... );
  41     }
  42
  43     template< class T >
  44     struct is_nullable
  45     {
  46     private:
  47             BOOST_STATIC_CONSTANT( T*, var );
  48     public:
  49
  50 #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
  51 #pragma warning(push)
  52 #pragma warning(disable:6334)
  53 #endif
  54
  55             BOOST_STATIC_CONSTANT(bool, value = sizeof( ptr_container_detail::is_nullable( var ) )
  56                                                 == sizeof( type_traits::yes_type ) );
  57 #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
  58 #pragma warning(pop)
  59 #endif
  60
  61     };
  62
  63     template< class T >
  64     struct remove_nullable
  65     {
  66         typedef BOOST_DEDUCED_TYPENAME mpl::eval_if< is_nullable<T>,
  67                                                       T,
  68                                             mpl::identity<T> >::type
  69             type;
  70     };
  71
  72     namespace ptr_container_detail
  73     {
  74         template< class T >
  75         struct void_ptr
  76         {
  77             typedef BOOST_DEDUCED_TYPENAME
  78                 mpl::if_c< boost::is_const<
  79                               BOOST_DEDUCED_TYPENAME boost::remove_nullable<T>::type >::value,
  80                            const void*, void* >::type type;
  81         };
  82     }
  83 }
  84
  85 #endif