// (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: | |
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION | |
template <typename T> | |
struct alignment_of<T&> | |
: alignment_of<T*> | |
{ | |
}; | |
#endif | |
#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 | |