| |
| // (C) Copyright John Maddock 2000. |
| // Use, modification and distribution are 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). |
| // |
| // See http://www.boost.org/libs/type_traits for most recent version including documentation. |
| |
| #ifndef BOOST_TT_ALIGNMENT_OF_HPP_INCLUDED |
| #define BOOST_TT_ALIGNMENT_OF_HPP_INCLUDED |
| |
| #include <boost/config.hpp> |
| #include <cstddef> |
| |
| #include <boost/type_traits/intrinsics.hpp> |
| // should be the last #include |
| #include <boost/type_traits/detail/size_t_trait_def.hpp> |
| |
| #ifdef BOOST_MSVC |
| # pragma warning(push) |
| # pragma warning(disable: 4121 4512) // alignment is sensitive to packing |
| #endif |
| #if defined(__BORLANDC__) && (__BORLANDC__ < 0x600) |
| #pragma option push -Vx- -Ve- |
| #endif |
| |
| namespace boost { |
| |
| template <typename T> struct alignment_of; |
| |
| // get the alignment of some arbitrary type: |
| namespace detail { |
| |
| #ifdef BOOST_MSVC |
| #pragma warning(push) |
| #pragma warning(disable:4324) // structure was padded due to __declspec(align()) |
| #endif |
| template <typename T> |
| struct alignment_of_hack |
| { |
| char c; |
| T t; |
| alignment_of_hack(); |
| }; |
| #ifdef BOOST_MSVC |
| #pragma warning(pop) |
| #endif |
| |
| template <unsigned A, unsigned S> |
| struct alignment_logic |
| { |
| BOOST_STATIC_CONSTANT(std::size_t, value = A < S ? A : S); |
| }; |
| |
| |
| template< typename T > |
| struct alignment_of_impl |
| { |
| #if defined(BOOST_MSVC) && (BOOST_MSVC >= 1400) |
| // |
| // With MSVC both the native __alignof operator |
| // and our own logic gets things wrong from time to time :-( |
| // Using a combination of the two seems to make the most of a bad job: |
| // |
| BOOST_STATIC_CONSTANT(std::size_t, value = |
| (::boost::detail::alignment_logic< |
| sizeof(::boost::detail::alignment_of_hack<T>) - sizeof(T), |
| __alignof(T) |
| >::value)); |
| #elif !defined(BOOST_ALIGNMENT_OF) |
| BOOST_STATIC_CONSTANT(std::size_t, value = |
| (::boost::detail::alignment_logic< |
| sizeof(::boost::detail::alignment_of_hack<T>) - sizeof(T), |
| sizeof(T) |
| >::value)); |
| #else |
| // |
| // We put this here, rather than in the definition of |
| // alignment_of below, because MSVC's __alignof doesn't |
| // always work in that context for some unexplained reason. |
| // (See type_with_alignment tests for test cases). |
| // |
| BOOST_STATIC_CONSTANT(std::size_t, value = BOOST_ALIGNMENT_OF(T)); |
| #endif |
| }; |
| |
| } // namespace detail |
| |
| BOOST_TT_AUX_SIZE_T_TRAIT_DEF1(alignment_of,T,::boost::detail::alignment_of_impl<T>::value) |
| |
| // references have to be treated specially, assume |
| // that a reference is just a special pointer: |
| template <typename T> |
| struct alignment_of<T&> |
| : public alignment_of<T*> |
| { |
| }; |
| #ifdef __BORLANDC__ |
| // long double gives an incorrect value of 10 (!) |
| // unless we do this... |
| struct long_double_wrapper{ long double ld; }; |
| template<> struct alignment_of<long double> |
| : public alignment_of<long_double_wrapper>{}; |
| #endif |
| |
| // void has to be treated specially: |
| BOOST_TT_AUX_SIZE_T_TRAIT_SPEC1(alignment_of,void,0) |
| #ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS |
| BOOST_TT_AUX_SIZE_T_TRAIT_SPEC1(alignment_of,void const,0) |
| BOOST_TT_AUX_SIZE_T_TRAIT_SPEC1(alignment_of,void volatile,0) |
| BOOST_TT_AUX_SIZE_T_TRAIT_SPEC1(alignment_of,void const volatile,0) |
| #endif |
| |
| } // namespace boost |
| |
| #if defined(__BORLANDC__) && (__BORLANDC__ < 0x600) |
| #pragma option pop |
| #endif |
| #ifdef BOOST_MSVC |
| # pragma warning(pop) |
| #endif |
| |
| #include <boost/type_traits/detail/size_t_trait_undef.hpp> |
| |
| #endif // BOOST_TT_ALIGNMENT_OF_HPP_INCLUDED |
| |