// (C) Copyright John Maddock 2000.
// Permission to copy, use, modify, sell and distribute this software is
// granted provided this copyright notice appears in all copies. This
// software is provided "as is" without express or implied warranty,
// and with no claim as to its suitability for any purpose.
#ifndef BOOST_TT_TYPE_WITH_ALIGNMENT_INCLUDED
#define BOOST_TT_TYPE_WITH_ALIGNMENT_INCLUDED
#include "boost/mpl/if.hpp"
#include "boost/preprocessor/list/for_each_i.hpp"
#include "boost/preprocessor/tuple/to_list.hpp"
#include "boost/preprocessor/cat.hpp"
#include "boost/type_traits/alignment_of.hpp"
#include "boost/type_traits/is_pod.hpp"
#include "boost/static_assert.hpp"
#include "boost/config.hpp"
// should be the last #include
#include "boost/type_traits/detail/bool_trait_def.hpp"
#include <cstddef>
#ifdef BOOST_MSVC
# pragma warning(push)
# pragma warning(disable: 4121) // alignment is sensitive to packing
#endif
namespace boost {
#ifndef __BORLANDC__
namespace detail {
class alignment_dummy;
typedef void (*function_ptr)();
typedef int (alignment_dummy::*member_ptr);
typedef int (alignment_dummy::*member_function_ptr)();
#define BOOST_TT_ALIGNMENT_TYPES BOOST_PP_TUPLE_TO_LIST( \
11, ( \
char, short, int, long, float, double, long double \
, void*, function_ptr, member_ptr, member_function_ptr))
#define BOOST_TT_CHOOSE_MIN_ALIGNMENT(R,P,I,T) \
typename mpl::if_c< \
alignment_of<T>::value <= target, T, char>::type BOOST_PP_CAT(t,I);
#define BOOST_TT_CHOOSE_T(R,P,I,T) T BOOST_PP_CAT(t,I);
template <std::size_t target>
union lower_alignment
{
BOOST_PP_LIST_FOR_EACH_I(
BOOST_TT_CHOOSE_MIN_ALIGNMENT
, ignored
, BOOST_TT_ALIGNMENT_TYPES
)
};
union max_align
{
BOOST_PP_LIST_FOR_EACH_I(
BOOST_TT_CHOOSE_T
, ignored
, BOOST_TT_ALIGNMENT_TYPES
)
};
#undef BOOST_TT_ALIGNMENT_TYPES
#undef BOOST_TT_CHOOSE_MIN_ALIGNMENT
#undef BOOST_TT_CHOOSE_T
template<int TAlign, int Align>
struct is_aligned
{
BOOST_STATIC_CONSTANT(bool,
value = (TAlign >= Align) & (TAlign % Align == 0)
);
};
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::detail::max_align,true)
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::detail::lower_alignment<1> ,true)
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::detail::lower_alignment<2> ,true)
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::detail::lower_alignment<4> ,true)
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::detail::lower_alignment<8> ,true)
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::detail::lower_alignment<10> ,true)
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::detail::lower_alignment<16> ,true)
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::detail::lower_alignment<32> ,true)
} // namespace detail
// This alignment method originally due to Brian Parker, implemented by David
// Abrahams, and then ported here by Doug Gregor.
template <int Align>
class type_with_alignment
{
typedef detail::lower_alignment<Align> t1;
typedef typename mpl::if_c<
::boost::detail::is_aligned< ::boost::alignment_of<t1>::value,Align >::value
, t1
, detail::max_align
>::type align_t;
BOOST_STATIC_CONSTANT(std::size_t, found = alignment_of<align_t>::value);
#ifndef __BORLANDC__
BOOST_STATIC_ASSERT(found >= Align);
BOOST_STATIC_ASSERT(found % Align == 0);
#else
BOOST_STATIC_ASSERT(::boost::type_with_alignment<Align>::found >= Align);
BOOST_STATIC_ASSERT(::boost::type_with_alignment<Align>::found % Align == 0);
#endif
public:
typedef align_t type;
};
#else
//
// Borland specific version, we have this for two reasons:
// 1) The version above doesn't always compile (with the new test cases for example)
// 2) Because of Borlands #pragma option we can create types with alignments that are
// greater that the largest aligned builtin type.
namespace align{
#pragma option push -a16
struct a2{ short s; };
struct a4{ int s; };
struct a8{ double s; };
struct a16{ long double s; };
#pragma option pop
}
namespace detail {
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::align::a2,true)
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::align::a4,true)
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::align::a8,true)
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::align::a16,true)
}
template <std::size_t N> struct type_with_alignment
{
// We should never get to here, but if we do use the maximally
// aligned type:
// BOOST_STATIC_ASSERT(0);
typedef align::a16 type;
};
template <> struct type_with_alignment<1>{ typedef char type; };
template <> struct type_with_alignment<2>{ typedef align::a2 type; };
template <> struct type_with_alignment<4>{ typedef align::a4 type; };
template <> struct type_with_alignment<8>{ typedef align::a8 type; };
template <> struct type_with_alignment<16>{ typedef align::a16 type; };
#endif
} // namespace boost
#ifdef BOOST_MSVC
# pragma warning(pop)
#endif
#include "boost/type_traits/detail/bool_trait_undef.hpp"
#endif // BOOST_TT_TYPE_WITH_ALIGNMENT_INCLUDED