//----------------------------------------------------------------------------- // boost aligned_storage.hpp header file // See http://www.boost.org for updates, documentation, and revision history. //----------------------------------------------------------------------------- // // Copyright (c) 2002-2003 // Eric Friedman, Itay Maman // // Distributed under 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) #ifndef BOOST_ALIGNED_STORAGE_HPP #define BOOST_ALIGNED_STORAGE_HPP #include <cstddef> // for std::size_t #include "boost/config.hpp" #include "boost/detail/workaround.hpp" #include "boost/type_traits/alignment_of.hpp" #include "boost/type_traits/type_with_alignment.hpp" #include "boost/type_traits/is_pod.hpp" #include "boost/mpl/eval_if.hpp" #include "boost/mpl/identity.hpp" #include "boost/type_traits/detail/bool_trait_def.hpp" namespace boost { namespace detail { namespace aligned_storage { BOOST_STATIC_CONSTANT( std::size_t , alignment_of_max_align = ::boost::alignment_of<max_align>::value ); // // To be TR1 conforming this must be a POD type: // template < std::size_t size_ , std::size_t alignment_ > struct aligned_storage_imp { union data_t { char buf[size_]; typename mpl::eval_if_c< alignment_ == std::size_t(-1) , mpl::identity<detail::max_align> , type_with_alignment<alignment_> >::type align_; } data_; void* address() const { return const_cast<aligned_storage_imp*>(this); } }; template< std::size_t alignment_ > struct aligned_storage_imp<0u,alignment_> { /* intentionally empty */ void* address() const { return 0; } }; }} // namespace detail::aligned_storage template < std::size_t size_ , std::size_t alignment_ = std::size_t(-1) > class aligned_storage : #ifndef __BORLANDC__ private #else public #endif detail::aligned_storage::aligned_storage_imp<size_, alignment_> { public: // constants typedef detail::aligned_storage::aligned_storage_imp<size_, alignment_> type; BOOST_STATIC_CONSTANT( std::size_t , size = size_ ); BOOST_STATIC_CONSTANT( std::size_t , alignment = ( alignment_ == std::size_t(-1) ? ::boost::detail::aligned_storage::alignment_of_max_align : alignment_ ) ); #if defined(__GNUC__) &&\ (__GNUC__ > 3) ||\ (__GNUC__ == 3 && (__GNUC_MINOR__ > 2 ||\ (__GNUC_MINOR__ == 2 && __GNUC_PATCHLEVEL__ >=3))) private: // noncopyable aligned_storage(const aligned_storage&); aligned_storage& operator=(const aligned_storage&); #else // gcc less than 3.2.3 public: // _should_ be noncopyable, but GCC compiler emits error aligned_storage(const aligned_storage&); aligned_storage& operator=(const aligned_storage&); #endif // gcc < 3.2.3 workaround public: // structors aligned_storage() { } ~aligned_storage() { } public: // accessors void* address() { return static_cast<type*>(this)->address(); } #if !BOOST_WORKAROUND(BOOST_MSVC, < 1300) const void* address() const { return static_cast<const type*>(this)->address(); } #else // MSVC6 const void* address() const; #endif // MSVC6 workaround }; #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) // MSVC6 seems not to like inline functions with const void* returns, so we // declare the following here: template <std::size_t S, std::size_t A> const void* aligned_storage<S,A>::address() const { return const_cast< aligned_storage<S,A>* >(this)->address(); } #endif // MSVC6 workaround #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION // // Make sure that is_pod recognises aligned_storage<>::type // as a POD (Note that aligned_storage<> itself is not a POD): // template <std::size_t size_, std::size_t alignment_> struct is_pod<boost::detail::aligned_storage::aligned_storage_imp<size_,alignment_> > BOOST_TT_AUX_BOOL_C_BASE(true) { BOOST_TT_AUX_BOOL_TRAIT_VALUE_DECL(true) }; #endif } // namespace boost #include "boost/type_traits/detail/bool_trait_undef.hpp" #endif // BOOST_ALIGNED_STORAGE_HPP