1 | |
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2 | // (C) Copyright Dave Abrahams, Steve Cleary, Beman Dawes, |
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3 | // Howard Hinnant and John Maddock 2000. |
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4 | // (C) Copyright Mat Marcus, Jesse Jones and Adobe Systems Inc 2001 |
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5 | |
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6 | // Use, modification and distribution are subject to the Boost Software License, |
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7 | // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
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8 | // http://www.boost.org/LICENSE_1_0.txt). |
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9 | // |
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10 | // See http://www.boost.org/libs/type_traits for most recent version including documentation. |
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11 | |
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12 | // Fixed is_pointer, is_reference, is_const, is_volatile, is_same, |
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13 | // is_member_pointer based on the Simulated Partial Specialization work |
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14 | // of Mat Marcus and Jesse Jones. See http://opensource.adobe.com or |
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15 | // http://groups.yahoo.com/group/boost/message/5441 |
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16 | // Some workarounds in here use ideas suggested from "Generic<Programming>: |
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17 | // Mappings between Types and Values" |
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18 | // by Andrei Alexandrescu (see http://www.cuj.com/experts/1810/alexandr.html). |
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19 | |
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20 | |
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21 | #ifndef BOOST_TT_IS_SAME_HPP_INCLUDED |
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22 | #define BOOST_TT_IS_SAME_HPP_INCLUDED |
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23 | |
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24 | #include <boost/type_traits/config.hpp> |
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25 | #ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION |
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26 | #include <boost/type_traits/detail/yes_no_type.hpp> |
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27 | #include <boost/type_traits/detail/ice_and.hpp> |
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28 | #include <boost/type_traits/is_reference.hpp> |
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29 | #endif |
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30 | // should be the last #include |
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31 | #include <boost/type_traits/detail/bool_trait_def.hpp> |
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32 | |
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33 | namespace boost { |
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34 | |
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35 | #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION |
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36 | |
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37 | BOOST_TT_AUX_BOOL_TRAIT_DEF2(is_same,T,U,false) |
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38 | BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC2_1(typename T,is_same,T,T,true) |
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39 | #if BOOST_WORKAROUND(__BORLANDC__, < 0x600) |
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40 | // without this, Borland's compiler gives the wrong answer for |
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41 | // references to arrays: |
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42 | BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC2_1(typename T,is_same,T&,T&,true) |
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43 | #endif |
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44 | |
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45 | #else // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION |
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46 | |
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47 | namespace detail { |
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48 | |
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49 | #ifdef BOOST_MSVC |
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50 | // the following VC6 specific implementation is *NOT* legal |
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51 | // C++, but has the advantage that it works for incomplete |
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52 | // types. |
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53 | |
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54 | template< typename T1 > |
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55 | struct is_same_part_1 |
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56 | { |
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57 | template<typename T2> struct part_2 { enum { value = false }; }; |
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58 | template<> struct part_2<T1> { enum { value = true }; }; |
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59 | }; |
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60 | |
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61 | template< typename T1, typename T2 > |
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62 | struct is_same_impl |
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63 | { |
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64 | enum { value = boost::detail::is_same_part_1<T1>::template part_2<T2>::value }; |
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65 | }; |
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66 | |
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67 | #else // generic "no-partial-specialization" version |
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68 | |
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69 | template <typename T> |
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70 | ::boost::type_traits::yes_type |
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71 | BOOST_TT_DECL is_same_tester(T*, T*); |
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72 | |
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73 | ::boost::type_traits::no_type |
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74 | BOOST_TT_DECL is_same_tester(...); |
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75 | |
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76 | template <typename T, typename U> |
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77 | struct is_same_impl |
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78 | { |
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79 | static T t; |
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80 | static U u; |
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81 | |
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82 | BOOST_STATIC_CONSTANT(bool, value = |
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83 | (::boost::type_traits::ice_and< |
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84 | (sizeof(type_traits::yes_type) == sizeof(boost::detail::is_same_tester(&t,&u))), |
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85 | (::boost::is_reference<T>::value == ::boost::is_reference<U>::value), |
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86 | (sizeof(T) == sizeof(U)) |
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87 | >::value)); |
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88 | }; |
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89 | |
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90 | #endif // BOOST_MSVC |
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91 | |
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92 | } // namespace detail |
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93 | |
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94 | BOOST_TT_AUX_BOOL_TRAIT_DEF2(is_same,T,U,(::boost::detail::is_same_impl<T,U>::value)) |
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95 | |
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96 | #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION |
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97 | |
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98 | } // namespace boost |
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99 | |
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100 | #include <boost/type_traits/detail/bool_trait_undef.hpp> |
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101 | |
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102 | #endif // BOOST_TT_IS_SAME_HPP_INCLUDED |
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103 | |
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