[857] | 1 |
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| 2 | // (C) Copyright John Maddock 2000.
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| 3 | // Use, modification and distribution are subject to the Boost Software License,
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| 4 | // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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| 5 | // http://www.boost.org/LICENSE_1_0.txt).
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| 6 | //
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| 7 | // See http://www.boost.org/libs/type_traits for most recent version including documentation.
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| 8 |
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| 9 | #ifndef BOOST_TT_ALIGNMENT_OF_HPP_INCLUDED
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| 10 | #define BOOST_TT_ALIGNMENT_OF_HPP_INCLUDED
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| 11 |
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| 12 | #include "boost/config.hpp"
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| 13 | #include <cstddef>
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| 14 |
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| 15 | // should be the last #include
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| 16 | #include "boost/type_traits/detail/size_t_trait_def.hpp"
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| 17 |
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| 18 | #ifdef BOOST_MSVC
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| 19 | # pragma warning(push)
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| 20 | # pragma warning(disable: 4121) // alignment is sensitive to packing
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| 21 | #endif
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| 22 | #if defined(__BORLANDC__) && (__BORLANDC__ < 0x600)
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| 23 | #pragma option push -Vx- -Ve-
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| 24 | #endif
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| 25 |
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| 26 | namespace boost {
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| 27 |
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| 28 | template <typename T> struct alignment_of;
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| 29 |
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| 30 | // get the alignment of some arbitrary type:
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| 31 | namespace detail {
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| 32 |
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| 33 | template <typename T>
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| 34 | struct alignment_of_hack
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| 35 | {
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| 36 | char c;
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| 37 | T t;
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| 38 | alignment_of_hack();
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| 39 | };
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| 40 |
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| 41 |
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| 42 | template <unsigned A, unsigned S>
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| 43 | struct alignment_logic
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| 44 | {
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| 45 | BOOST_STATIC_CONSTANT(std::size_t, value = A < S ? A : S);
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| 46 | };
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| 47 |
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| 48 |
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| 49 | template< typename T >
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| 50 | struct alignment_of_impl
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| 51 | {
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| 52 | BOOST_STATIC_CONSTANT(std::size_t, value =
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| 53 | (::boost::detail::alignment_logic<
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| 54 | sizeof(detail::alignment_of_hack<T>) - sizeof(T),
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| 55 | sizeof(T)
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| 56 | >::value));
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| 57 | };
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| 58 |
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| 59 | } // namespace detail
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| 60 |
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| 61 | BOOST_TT_AUX_SIZE_T_TRAIT_DEF1(alignment_of,T,::boost::detail::alignment_of_impl<T>::value)
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| 62 |
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| 63 | // references have to be treated specially, assume
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| 64 | // that a reference is just a special pointer:
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| 65 | #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
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| 66 | template <typename T>
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| 67 | struct alignment_of<T&>
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| 68 | : alignment_of<T*>
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| 69 | {
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| 70 | };
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| 71 | #endif
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| 72 | #ifdef __BORLANDC__
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| 73 | // long double gives an incorrect value of 10 (!)
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| 74 | // unless we do this...
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| 75 | struct long_double_wrapper{ long double ld; };
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| 76 | template<> struct alignment_of<long double>
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| 77 | : public alignment_of<long_double_wrapper>{};
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| 78 | #endif
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| 79 |
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| 80 | // void has to be treated specially:
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| 81 | BOOST_TT_AUX_SIZE_T_TRAIT_SPEC1(alignment_of,void,0)
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| 82 | #ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS
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| 83 | BOOST_TT_AUX_SIZE_T_TRAIT_SPEC1(alignment_of,void const,0)
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| 84 | BOOST_TT_AUX_SIZE_T_TRAIT_SPEC1(alignment_of,void volatile,0)
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| 85 | BOOST_TT_AUX_SIZE_T_TRAIT_SPEC1(alignment_of,void const volatile,0)
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| 86 | #endif
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| 87 |
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| 88 | } // namespace boost
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| 89 |
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| 90 | #if defined(__BORLANDC__) && (__BORLANDC__ < 0x600)
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| 91 | #pragma option pop
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| 92 | #endif
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| 93 | #ifdef BOOST_MSVC
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| 94 | # pragma warning(pop)
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| 95 | #endif
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| 96 |
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| 97 | #include "boost/type_traits/detail/size_t_trait_undef.hpp"
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| 98 |
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| 99 | #endif // BOOST_TT_ALIGNMENT_OF_HPP_INCLUDED
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| 100 |
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