Chris@16: //-----------------------------------------------------------------------------
Chris@16: // boost aligned_storage.hpp header file
Chris@16: // See http://www.boost.org for updates, documentation, and revision history.
Chris@16: //-----------------------------------------------------------------------------
Chris@16: //
Chris@16: // Copyright (c) 2002-2003
Chris@16: // Eric Friedman, Itay Maman
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_ALIGNED_STORAGE_HPP
Chris@16: #define BOOST_ALIGNED_STORAGE_HPP
Chris@16: 
Chris@16: #include <cstddef> // for std::size_t
Chris@16: 
Chris@16: #include "boost/config.hpp"
Chris@16: #include "boost/detail/workaround.hpp"
Chris@16: #include "boost/type_traits/alignment_of.hpp"
Chris@16: #include "boost/type_traits/type_with_alignment.hpp"
Chris@16: #include "boost/type_traits/is_pod.hpp"
Chris@16: 
Chris@16: #include "boost/mpl/eval_if.hpp"
Chris@16: #include "boost/mpl/identity.hpp"
Chris@16: 
Chris@16: #include "boost/type_traits/detail/bool_trait_def.hpp"
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: namespace detail { namespace aligned_storage {
Chris@16: 
Chris@16: BOOST_STATIC_CONSTANT(
Chris@16:       std::size_t
Chris@16:     , alignment_of_max_align = ::boost::alignment_of<max_align>::value
Chris@16:     );
Chris@16: 
Chris@16: //
Chris@16: // To be TR1 conforming this must be a POD type:
Chris@16: //
Chris@16: template <
Chris@16:       std::size_t size_
Chris@16:     , std::size_t alignment_
Chris@16: >
Chris@16: struct aligned_storage_imp
Chris@16: {
Chris@16:     union data_t
Chris@16:     {
Chris@16:         char buf[size_];
Chris@16: 
Chris@101:         typename ::boost::mpl::eval_if_c<
Chris@16:               alignment_ == std::size_t(-1)
Chris@101:             , ::boost::mpl::identity< ::boost::detail::max_align >
Chris@101:             , ::boost::type_with_alignment<alignment_>
Chris@16:             >::type align_;
Chris@16:     } data_;
Chris@16:     void* address() const { return const_cast<aligned_storage_imp*>(this); }
Chris@16: };
Chris@16: 
Chris@16: template< std::size_t alignment_ >
Chris@16: struct aligned_storage_imp<0u,alignment_>
Chris@16: {
Chris@16:     /* intentionally empty */
Chris@16:     void* address() const { return 0; }
Chris@16: };
Chris@16: 
Chris@16: }} // namespace detail::aligned_storage
Chris@16: 
Chris@16: template <
Chris@16:       std::size_t size_
Chris@16:     , std::size_t alignment_ = std::size_t(-1)
Chris@16: >
Chris@16: class aligned_storage : 
Chris@16: #ifndef __BORLANDC__
Chris@16:    private 
Chris@16: #else
Chris@16:    public
Chris@16: #endif
Chris@101:    ::boost::detail::aligned_storage::aligned_storage_imp<size_, alignment_> 
Chris@16: {
Chris@16:  
Chris@16: public: // constants
Chris@16: 
Chris@101:     typedef ::boost::detail::aligned_storage::aligned_storage_imp<size_, alignment_> type;
Chris@16: 
Chris@16:     BOOST_STATIC_CONSTANT(
Chris@16:           std::size_t
Chris@16:         , size = size_
Chris@16:         );
Chris@16:     BOOST_STATIC_CONSTANT(
Chris@16:           std::size_t
Chris@16:         , alignment = (
Chris@16:               alignment_ == std::size_t(-1)
Chris@16:             ? ::boost::detail::aligned_storage::alignment_of_max_align
Chris@16:             : alignment_
Chris@16:             )
Chris@16:         );
Chris@16: 
Chris@16: private: // noncopyable
Chris@16: 
Chris@16:     aligned_storage(const aligned_storage&);
Chris@16:     aligned_storage& operator=(const aligned_storage&);
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@16:     aligned_storage()
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     ~aligned_storage()
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: public: // accessors
Chris@16: 
Chris@16:     void* address()
Chris@16:     {
Chris@16:         return static_cast<type*>(this)->address();
Chris@16:     }
Chris@16: 
Chris@16:     const void* address() const
Chris@16:     {
Chris@16:         return static_cast<const type*>(this)->address();
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //
Chris@16: // Make sure that is_pod recognises aligned_storage<>::type
Chris@16: // as a POD (Note that aligned_storage<> itself is not a POD):
Chris@16: //
Chris@16: template <std::size_t size_, std::size_t alignment_>
Chris@101: struct is_pod< ::boost::detail::aligned_storage::aligned_storage_imp<size_,alignment_> >
Chris@16:    BOOST_TT_AUX_BOOL_C_BASE(true)
Chris@16: { 
Chris@16:     BOOST_TT_AUX_BOOL_TRAIT_VALUE_DECL(true)
Chris@16: }; 
Chris@16: 
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include "boost/type_traits/detail/bool_trait_undef.hpp"
Chris@16: 
Chris@16: #endif // BOOST_ALIGNED_STORAGE_HPP