// This alignment method originally due to Brian Parker, implemented by David
// Abrahams, and then ported here by Doug Gregor.
+namespace detail{
+
template <std::size_t Align>
-class type_with_alignment
+class type_with_alignment_imp
{
typedef ::boost::detail::lower_alignment<Align> t1;
typedef typename mpl::if_c<
typedef align_t type;
};
+}
+
+template <std::size_t Align>
+class type_with_alignment
+ : public ::boost::detail::type_with_alignment_imp<Align>
+{
+};
+
#if defined(__GNUC__)
namespace align {
struct __attribute__((__aligned__(2))) a2 {};
BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::align::a32,true)
}
#endif
+#if (defined(BOOST_MSVC) || (defined(BOOST_INTEL) && defined(_MSC_VER))) && _MSC_VER >= 1300
+//
+// 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 http://article.gmane.org/gmane.comp.lib.boost.devel/173011
+// 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 align {
+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<> class type_with_alignment<8>
+{
+ typedef mpl::if_c<
+ ::boost::alignment_of<detail::max_align>::value < 8,
+ align::a8,
+ detail::type_with_alignment_imp<8> >::type t1;
+public:
+ typedef t1::type type;
+};
+template<> class type_with_alignment<16>
+{
+ typedef mpl::if_c<
+ ::boost::alignment_of<detail::max_align>::value < 16,
+ align::a16,
+ detail::type_with_alignment_imp<16> >::type t1;
+public:
+ typedef t1::type type;
+};
+template<> class type_with_alignment<32>
+{
+ typedef mpl::if_c<
+ ::boost::alignment_of<detail::max_align>::value < 32,
+ align::a32,
+ detail::type_with_alignment_imp<32> >::type t1;
+public:
+ typedef t1::type type;
+};
+template<> class type_with_alignment<64> {
+ typedef mpl::if_c<
+ ::boost::alignment_of<detail::max_align>::value < 64,
+ align::a64,
+ detail::type_with_alignment_imp<64> >::type t1;
+public:
+ typedef t1::type type;
+};
+template<> class type_with_alignment<128> {
+ typedef mpl::if_c<
+ ::boost::alignment_of<detail::max_align>::value < 128,
+ align::a128,
+ detail::type_with_alignment_imp<128> >::type t1;
+public:
+ typedef t1::type type;
+};
+
+namespace detail {
+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)
+BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::align::a32,true)
+BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::align::a64,true)
+BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_pod,::boost::align::a128,true)
+}
+#endif
#else
typedef ::boost::align::a16 max_align;
+//#if ! BOOST_WORKAROUND(__CODEGEARC__, BOOST_TESTED_AT(0x610))
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)
+//#endif
}
template <std::size_t N> struct type_with_alignment