1 | // (C) Copyright John Maddock 2000. |
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2 | // Use, modification and distribution are subject to the Boost Software License, |
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3 | // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
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4 | // http://www.boost.org/LICENSE_1_0.txt). |
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5 | // |
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6 | // See http://www.boost.org/libs/type_traits for most recent version including documentation. |
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7 | |
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8 | #ifndef BOOST_TT_IS_POLYMORPHIC_HPP |
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9 | #define BOOST_TT_IS_POLYMORPHIC_HPP |
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10 | |
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11 | #include <boost/type_traits/intrinsics.hpp> |
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12 | #ifndef BOOST_IS_POLYMORPHIC |
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13 | #include <boost/type_traits/is_class.hpp> |
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14 | #include <boost/type_traits/remove_cv.hpp> |
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15 | #endif |
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16 | // should be the last #include |
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17 | #include <boost/type_traits/detail/bool_trait_def.hpp> |
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18 | #include <boost/detail/workaround.hpp> |
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19 | |
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20 | namespace boost{ |
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21 | |
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22 | #ifndef BOOST_IS_POLYMORPHIC |
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23 | |
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24 | namespace detail{ |
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25 | |
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26 | template <class T> |
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27 | struct is_polymorphic_imp1 |
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28 | { |
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29 | # if BOOST_WORKAROUND(__MWERKS__, <= 0x2407) // CWPro7 should return false always. |
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30 | typedef char d1, (&d2)[2]; |
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31 | # else |
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32 | typedef typename remove_cv<T>::type ncvT; |
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33 | struct d1 : public ncvT |
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34 | { |
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35 | d1(); |
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36 | # if !defined(__GNUC__) // this raises warnings with some classes, and buys nothing with GCC |
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37 | ~d1()throw(); |
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38 | # endif |
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39 | char padding[256]; |
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40 | private: |
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41 | // keep some picky compilers happy: |
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42 | d1(const d1&); |
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43 | d1& operator=(const d1&); |
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44 | }; |
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45 | struct d2 : public ncvT |
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46 | { |
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47 | d2(); |
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48 | virtual ~d2()throw(); |
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49 | # if !defined(BOOST_MSVC) && !defined(__ICL) |
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50 | // for some reason this messes up VC++ when T has virtual bases, |
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51 | // probably likewise for compilers that use the same ABI: |
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52 | struct unique{}; |
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53 | virtual void unique_name_to_boost5487629(unique*); |
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54 | # endif |
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55 | char padding[256]; |
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56 | private: |
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57 | // keep some picky compilers happy: |
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58 | d2(const d2&); |
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59 | d2& operator=(const d2&); |
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60 | }; |
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61 | # endif |
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62 | BOOST_STATIC_CONSTANT(bool, value = (sizeof(d2) == sizeof(d1))); |
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63 | }; |
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64 | |
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65 | template <class T> |
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66 | struct is_polymorphic_imp2 |
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67 | { |
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68 | BOOST_STATIC_CONSTANT(bool, value = false); |
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69 | }; |
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70 | |
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71 | template <bool is_class> |
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72 | struct is_polymorphic_selector |
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73 | { |
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74 | template <class T> |
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75 | struct rebind |
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76 | { |
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77 | typedef is_polymorphic_imp2<T> type; |
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78 | }; |
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79 | }; |
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80 | |
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81 | template <> |
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82 | struct is_polymorphic_selector<true> |
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83 | { |
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84 | template <class T> |
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85 | struct rebind |
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86 | { |
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87 | typedef is_polymorphic_imp1<T> type; |
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88 | }; |
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89 | }; |
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90 | |
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91 | template <class T> |
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92 | struct is_polymorphic_imp |
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93 | { |
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94 | typedef is_polymorphic_selector< ::boost::is_class<T>::value> selector; |
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95 | typedef typename selector::template rebind<T> binder; |
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96 | typedef typename binder::type imp_type; |
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97 | BOOST_STATIC_CONSTANT(bool, value = imp_type::value); |
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98 | }; |
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99 | |
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100 | } // namespace detail |
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101 | |
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102 | BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_polymorphic,T,::boost::detail::is_polymorphic_imp<T>::value) |
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103 | |
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104 | #else // BOOST_IS_POLYMORPHIC |
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105 | |
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106 | BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_polymorphic,T,BOOST_IS_POLYMORPHIC(T)) |
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107 | |
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108 | #endif |
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109 | |
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110 | } // namespace boost |
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111 | |
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112 | #include <boost/type_traits/detail/bool_trait_undef.hpp> |
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113 | |
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114 | #endif |
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