//  (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_TYPE_WITH_ALIGNMENT_INCLUDED
#define BOOST_TT_TYPE_WITH_ALIGNMENT_INCLUDED

#include <boost/type_traits/alignment_of.hpp>
#include <boost/type_traits/is_pod.hpp>
#include <boost/static_assert.hpp>
#include <boost/config.hpp>
#include <cstddef> // size_t
#include <boost/detail/workaround.hpp>

#ifdef BOOST_MSVC
#   pragma warning(push)
#   pragma warning(disable: 4121) // alignment is sensitive to packing
#endif

#ifdef _MSC_VER
#include <boost/type_traits/conditional.hpp>
#endif

namespace boost {
#ifndef BOOST_BORLANDC
namespace detail {

union max_align
{
    char c;
    short s;
    int i;
    long l;
#ifndef BOOST_NO_LONG_LONG
    boost::long_long_type ll;
#endif
#ifdef BOOST_HAS_INT128
    boost::int128_type i128;
#endif
    float f;
    double d;
    long double ld;
#ifdef BOOST_HAS_FLOAT128
    __float128 f128;
#endif
};

template <std::size_t Target, bool check> struct long_double_alignment
{
    typedef long double type;
};
template <std::size_t Target> struct long_double_alignment<Target, false>
{
    typedef boost::detail::max_align type;
};

template <std::size_t Target, bool check> struct double_alignment
{
    typedef double type;
};
template <std::size_t Target> struct double_alignment<Target, false>
{
    typedef typename long_double_alignment<Target, boost::alignment_of<long double>::value >= Target>::type type;
};

#ifndef BOOST_NO_LONG_LONG
template <std::size_t Target, bool check> struct long_long_alignment
{
    typedef boost::long_long_type type;
};
template <std::size_t Target> struct long_long_alignment<Target, false>
{
    typedef typename double_alignment<Target, boost::alignment_of<double>::value >= Target>::type type;
};
#endif

template <std::size_t Target, bool check> struct long_alignment
{
    typedef long type;
};
#ifndef BOOST_NO_LONG_LONG
template <std::size_t Target> struct long_alignment<Target, false>
{
    typedef typename long_long_alignment<Target, boost::alignment_of<boost::long_long_type>::value >= Target>::type type;
};
#else
template <std::size_t Target> struct long_alignment<Target, false>
{
    typedef typename double_alignment<Target, boost::alignment_of<double>::value >= Target>::type type;
};
#endif

template <std::size_t Target, bool check> struct int_alignment
{
    typedef int type;
};
template <std::size_t Target> struct int_alignment<Target, false>
{
    typedef typename long_alignment<Target, boost::alignment_of<long>::value >= Target>::type type;
};

template <std::size_t Target, bool check> struct short_alignment
{
    typedef short type;
};
template <std::size_t Target> struct short_alignment<Target, false>
{
    typedef typename int_alignment<Target, boost::alignment_of<int>::value >= Target>::type type;
};

template <std::size_t Target, bool check> struct char_alignment
{
    typedef char type;
};
template <std::size_t Target> struct char_alignment<Target, false>
{
    typedef typename short_alignment<Target, boost::alignment_of<short>::value >= Target>::type type;
};

} // namespace detail

template <std::size_t Align>
struct type_with_alignment
{
    typedef typename boost::detail::char_alignment<Align, boost::alignment_of<char>::value >= Align>::type type;
};

#if (defined(__GNUC__) || (defined (__SUNPRO_CC) &&  (__SUNPRO_CC >= 0x5130)) || defined(__clang__)) && !defined(BOOST_TT_DISABLE_INTRINSICS)
namespace tt_align_ns {
struct __attribute__((__aligned__(2))) a2 {};
struct __attribute__((__aligned__(4))) a4 {};
struct __attribute__((__aligned__(8))) a8 {};
struct __attribute__((__aligned__(16))) a16 {};
struct __attribute__((__aligned__(32))) a32 {};
struct __attribute__((__aligned__(64))) a64 {};
struct __attribute__((__aligned__(128))) a128 {};
}

template<> struct type_with_alignment<1>
{
  public:
    typedef char type;
};
template<> struct type_with_alignment<2>
{
  public:
    typedef tt_align_ns::a2 type;
};
template<> struct type_with_alignment<4>
{
  public:
    typedef tt_align_ns::a4 type;
};
template<> struct type_with_alignment<8>
{
  public:
    typedef tt_align_ns::a8 type;
};
template<> struct type_with_alignment<16>
{
  public:
    typedef tt_align_ns::a16 type;
};
template<> struct type_with_alignment<32>
{
  public:
    typedef tt_align_ns::a32 type;
};
template<> struct type_with_alignment<64>
{
  public:
    typedef tt_align_ns::a64 type;
};
template<> struct type_with_alignment<128>
{
  public:
    typedef tt_align_ns::a128 type;
};

template<> struct is_pod< ::boost::tt_align_ns::a2> : public true_type {};
template<> struct is_pod< ::boost::tt_align_ns::a4> : public true_type {};
template<> struct is_pod< ::boost::tt_align_ns::a8> : public true_type {};
template<> struct is_pod< ::boost::tt_align_ns::a16> : public true_type {};
template<> struct is_pod< ::boost::tt_align_ns::a32> : public true_type {};
template<> struct is_pod< ::boost::tt_align_ns::a64> : public true_type {};
template<> struct is_pod< ::boost::tt_align_ns::a128> : public true_type {};

#endif
#if (defined(BOOST_MSVC) || (defined(BOOST_INTEL) && defined(_MSC_VER))) && !defined(BOOST_TT_DISABLE_INTRINSICS)
//
// MSVC supports types which have alignments greater than the normal
// maximum: these are used for example in the types __m64 and __m128
// to provide types with alignment requirements which match the SSE
// registers.  Therefore we extend type_with_alignment<> to support
// such types, however, we have to be careful to use a builtin type
// whenever possible otherwise we break previously working code:
// see https://lists.boost.org/Archives/boost/2014/03/212391.php
// for an example and test case.  Thus types like a8 below will
// be used *only* if the existing implementation can't provide a type
// with suitable alignment.  This does mean however, that type_with_alignment<>
// may return a type which cannot be passed through a function call
// by value (and neither can any type containing such a type like
// Boost.Optional).  However, this only happens when we have no choice
// in the matter because no other "ordinary" type is available.
//
namespace tt_align_ns {
struct __declspec(align(8)) a8
{
    char m[8];
    typedef a8 type;
};
struct __declspec(align(16)) a16
{
    char m[16];
    typedef a16 type;
};
struct __declspec(align(32)) a32
{
    char m[32];
    typedef a32 type;
};
struct __declspec(align(64)) a64
{
    char m[64];
    typedef a64 type;
};
struct __declspec(align(128)) a128
{
    char m[128];
    typedef a128 type;
};
}

template<> struct type_with_alignment<8>
{
    typedef boost::conditional<
    ::boost::alignment_of<boost::detail::max_align>::value < 8,
    tt_align_ns::a8,
    boost::detail::char_alignment<8, false> >::type t1;
  public:
    typedef t1::type type;
};
template<> struct type_with_alignment<16>
{
    typedef boost::conditional<
    ::boost::alignment_of<boost::detail::max_align>::value < 16,
    tt_align_ns::a16,
    boost::detail::char_alignment<16, false> >::type t1;
  public:
    typedef t1::type type;
};
template<> struct type_with_alignment<32>
{
    typedef boost::conditional<
    ::boost::alignment_of<boost::detail::max_align>::value < 32,
    tt_align_ns::a32,
    boost::detail::char_alignment<32, false> >::type t1;
  public:
    typedef t1::type type;
};
template<> struct type_with_alignment<64>
{
    typedef boost::conditional<
    ::boost::alignment_of<boost::detail::max_align>::value < 64,
    tt_align_ns::a64,
    boost::detail::char_alignment<64, false> >::type t1;
  public:
    typedef t1::type type;
};
template<> struct type_with_alignment<128>
{
    typedef boost::conditional<
    ::boost::alignment_of<boost::detail::max_align>::value < 128,
    tt_align_ns::a128,
    boost::detail::char_alignment<128, false> >::type t1;
  public:
    typedef t1::type type;
};

template<> struct is_pod< ::boost::tt_align_ns::a8> : public true_type {};
template<> struct is_pod< ::boost::tt_align_ns::a16> : public true_type {};
template<> struct is_pod< ::boost::tt_align_ns::a32> : public true_type {};
template<> struct is_pod< ::boost::tt_align_ns::a64> : public true_type {};
template<> struct is_pod< ::boost::tt_align_ns::a128> : public true_type {};

#endif

#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 tt_align_ns {
#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 {

typedef ::boost::tt_align_ns::a16 max_align;

}
//#if ! BOOST_WORKAROUND(BOOST_CODEGEARC, BOOST_TESTED_AT(0x610))
template <> struct is_pod< ::boost::tt_align_ns::a2> : public true_type {};
template <> struct is_pod< ::boost::tt_align_ns::a4> : public true_type {};
template <> struct is_pod< ::boost::tt_align_ns::a8> : public true_type {};
template <> struct is_pod< ::boost::tt_align_ns::a16> : public true_type {};
//#endif

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 tt_align_ns::a16 type;
};
template <> struct type_with_alignment<1>
{
    typedef char type;
};
template <> struct type_with_alignment<2>
{
    typedef tt_align_ns::a2 type;
};
template <> struct type_with_alignment<4>
{
    typedef tt_align_ns::a4 type;
};
template <> struct type_with_alignment<8>
{
    typedef tt_align_ns::a8 type;
};
template <> struct type_with_alignment<16>
{
    typedef tt_align_ns::a16 type;
};

#endif

} // namespace boost

#ifdef BOOST_MSVC
#   pragma warning(pop)
#endif

#endif // BOOST_TT_TYPE_WITH_ALIGNMENT_INCLUDED
