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- //
- // Boost.Pointer Container
- //
- // Copyright Thorsten Ottosen 2003-2005. Use, modification and
- // distribution is subject to the Boost Software License, Version
- // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
- // http://www.boost.org/LICENSE_1_0.txt)
- //
- // For more information, see http://www.boost.org/libs/ptr_container/
- //
- #ifndef BOOST_INDIRECT_CONTAINER_NULLABLE_HPP
- #define BOOST_INDIRECT_CONTAINER_NULLABLE_HPP
- #if defined(_MSC_VER) && (_MSC_VER >= 1200)
- # pragma once
- #endif
- #include <boost/type_traits/detail/yes_no_type.hpp>
- #include <boost/type_traits/is_const.hpp>
- #include <boost/mpl/eval_if.hpp>
- #include <boost/mpl/identity.hpp>
- #include <boost/config.hpp>
- namespace boost
- {
-
- template< class T >
- struct nullable
- {
- typedef T type;
- };
- namespace ptr_container_detail
- {
- template< class T >
- type_traits::yes_type is_nullable( const nullable<T>* );
- type_traits::no_type is_nullable( ... );
- }
- template< class T >
- struct is_nullable
- {
- private:
- BOOST_STATIC_CONSTANT( T*, var );
- public:
- #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
- #pragma warning(push)
- #pragma warning(disable:6334)
- #endif
- BOOST_STATIC_CONSTANT(bool, value = sizeof( ptr_container_detail::is_nullable( var ) )
- == sizeof( type_traits::yes_type ) );
- #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
- #pragma warning(pop)
- #endif
-
- };
-
- template< class T >
- struct remove_nullable
- {
- typedef BOOST_DEDUCED_TYPENAME mpl::eval_if< is_nullable<T>,
- T,
- mpl::identity<T> >::type
- type;
- };
- namespace ptr_container_detail
- {
- template< class T >
- struct void_ptr
- {
- typedef BOOST_DEDUCED_TYPENAME
- mpl::if_c< boost::is_const<
- BOOST_DEDUCED_TYPENAME boost::remove_nullable<T>::type >::value,
- const void*, void* >::type type;
- };
- }
- }
- #endif
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