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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_REFERENCE_HPP_INCLUDED |
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22 #define BOOST_TT_IS_REFERENCE_HPP_INCLUDED |
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23 |
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24 #include <boost/type_traits/config.hpp> |
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25 |
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26 #ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION |
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27 # include <boost/type_traits/detail/yes_no_type.hpp> |
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28 # include <boost/type_traits/detail/wrap.hpp> |
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29 #endif |
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30 |
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31 // should be the last #include |
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32 #include <boost/type_traits/detail/bool_trait_def.hpp> |
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33 |
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34 namespace boost { |
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35 |
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36 #if defined( __CODEGEARC__ ) |
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37 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_reference,T,__is_reference(T)) |
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38 #elif !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) |
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39 |
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40 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_reference,T,false) |
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41 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T&,true) |
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42 |
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43 #if defined(BOOST_ILLEGAL_CV_REFERENCES) |
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44 // these are illegal specialisations; cv-qualifies applied to |
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45 // references have no effect according to [8.3.2p1], |
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46 // C++ Builder requires them though as it treats cv-qualified |
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47 // references as distinct types... |
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48 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T& const,true) |
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49 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T& volatile,true) |
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50 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T& const volatile,true) |
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51 #endif |
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52 |
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53 #if defined(__GNUC__) && (__GNUC__ < 3) |
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54 // these allow us to work around illegally cv-qualified reference |
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55 // types. |
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56 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T const ,::boost::is_reference<T>::value) |
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57 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T volatile ,::boost::is_reference<T>::value) |
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58 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T const volatile ,::boost::is_reference<T>::value) |
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59 // However, the above specializations confuse gcc 2.96 unless we also |
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60 // supply these specializations for array types |
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61 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_2(typename T,unsigned long N,is_reference,T[N],false) |
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62 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_2(typename T,unsigned long N,is_reference,const T[N],false) |
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63 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_2(typename T,unsigned long N,is_reference,volatile T[N],false) |
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64 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_2(typename T,unsigned long N,is_reference,const volatile T[N],false) |
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65 #endif |
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66 |
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67 #else |
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68 |
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69 #ifdef BOOST_MSVC |
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70 # pragma warning(push) |
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71 # pragma warning(disable: 4181 4097) |
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72 #endif |
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73 |
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74 namespace detail { |
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75 |
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76 using ::boost::type_traits::yes_type; |
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77 using ::boost::type_traits::no_type; |
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78 using ::boost::type_traits::wrap; |
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79 |
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80 template <class T> T&(* is_reference_helper1(wrap<T>) )(wrap<T>); |
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81 char is_reference_helper1(...); |
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82 |
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83 template <class T> no_type is_reference_helper2(T&(*)(wrap<T>)); |
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84 yes_type is_reference_helper2(...); |
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85 |
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86 template <typename T> |
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87 struct is_reference_impl |
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88 { |
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89 BOOST_STATIC_CONSTANT( |
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90 bool, value = sizeof( |
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91 ::boost::detail::is_reference_helper2( |
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92 ::boost::detail::is_reference_helper1(::boost::type_traits::wrap<T>()))) == 1 |
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93 ); |
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94 }; |
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95 |
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96 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_reference,void,false) |
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97 #ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS |
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98 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_reference,void const,false) |
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99 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_reference,void volatile,false) |
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100 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_reference,void const volatile,false) |
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101 #endif |
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102 |
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103 } // namespace detail |
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104 |
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105 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_reference,T,::boost::detail::is_reference_impl<T>::value) |
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106 |
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107 #ifdef BOOST_MSVC |
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108 # pragma warning(pop) |
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109 #endif |
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110 |
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111 #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION |
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112 |
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113 } // namespace boost |
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114 |
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115 #include <boost/type_traits/detail/bool_trait_undef.hpp> |
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116 |
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117 #endif // BOOST_TT_IS_REFERENCE_HPP_INCLUDED |
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118 |