[44] | 1 | // (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & 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/utility for most recent version including documentation. |
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| 7 | |
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| 8 | // compressed_pair: pair that "compresses" empty members |
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| 9 | // (see libs/utility/compressed_pair.htm) |
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| 10 | // |
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| 11 | // JM changes 25 Jan 2004: |
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| 12 | // For the case where T1 == T2 and both are empty, then first() and second() |
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| 13 | // should return different objects. |
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| 14 | // JM changes 25 Jan 2000: |
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| 15 | // Removed default arguments from compressed_pair_switch to get |
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| 16 | // C++ Builder 4 to accept them |
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| 17 | // rewriten swap to get gcc and C++ builder to compile. |
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| 18 | // added partial specialisations for case T1 == T2 to avoid duplicate constructor defs. |
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| 19 | |
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| 20 | #ifndef BOOST_DETAIL_COMPRESSED_PAIR_HPP |
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| 21 | #define BOOST_DETAIL_COMPRESSED_PAIR_HPP |
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| 22 | |
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| 23 | #include <algorithm> |
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| 24 | |
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| 25 | #include <boost/type_traits/remove_cv.hpp> |
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| 26 | #include <boost/type_traits/is_empty.hpp> |
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| 27 | #include <boost/type_traits/is_same.hpp> |
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| 28 | #include <boost/call_traits.hpp> |
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| 29 | |
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| 30 | #ifdef BOOST_MSVC |
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| 31 | # pragma warning(push) |
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| 32 | # pragma warning(disable:4512) |
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| 33 | #endif |
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| 34 | namespace boost |
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| 35 | { |
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| 36 | |
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| 37 | template <class T1, class T2> |
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| 38 | class compressed_pair; |
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| 39 | |
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| 40 | |
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| 41 | // compressed_pair |
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| 42 | |
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| 43 | namespace details |
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| 44 | { |
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| 45 | // JM altered 26 Jan 2000: |
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| 46 | template <class T1, class T2, bool IsSame, bool FirstEmpty, bool SecondEmpty> |
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| 47 | struct compressed_pair_switch; |
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| 48 | |
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| 49 | template <class T1, class T2> |
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| 50 | struct compressed_pair_switch<T1, T2, false, false, false> |
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| 51 | {static const int value = 0;}; |
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| 52 | |
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| 53 | template <class T1, class T2> |
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| 54 | struct compressed_pair_switch<T1, T2, false, true, true> |
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| 55 | {static const int value = 3;}; |
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| 56 | |
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| 57 | template <class T1, class T2> |
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| 58 | struct compressed_pair_switch<T1, T2, false, true, false> |
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| 59 | {static const int value = 1;}; |
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| 60 | |
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| 61 | template <class T1, class T2> |
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| 62 | struct compressed_pair_switch<T1, T2, false, false, true> |
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| 63 | {static const int value = 2;}; |
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| 64 | |
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| 65 | template <class T1, class T2> |
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| 66 | struct compressed_pair_switch<T1, T2, true, true, true> |
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| 67 | {static const int value = 4;}; |
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| 68 | |
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| 69 | template <class T1, class T2> |
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| 70 | struct compressed_pair_switch<T1, T2, true, false, false> |
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| 71 | {static const int value = 5;}; |
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| 72 | |
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| 73 | template <class T1, class T2, int Version> class compressed_pair_imp; |
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| 74 | |
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| 75 | #ifdef __GNUC__ |
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| 76 | // workaround for GCC (JM): |
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| 77 | using std::swap; |
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| 78 | #endif |
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| 79 | // |
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| 80 | // can't call unqualified swap from within classname::swap |
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| 81 | // as Koenig lookup rules will find only the classname::swap |
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| 82 | // member function not the global declaration, so use cp_swap |
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| 83 | // as a forwarding function (JM): |
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| 84 | template <typename T> |
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| 85 | inline void cp_swap(T& t1, T& t2) |
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| 86 | { |
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| 87 | #ifndef __GNUC__ |
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| 88 | using std::swap; |
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| 89 | #endif |
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| 90 | swap(t1, t2); |
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| 91 | } |
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| 92 | |
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| 93 | // 0 derive from neither |
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| 94 | |
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| 95 | template <class T1, class T2> |
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| 96 | class compressed_pair_imp<T1, T2, 0> |
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| 97 | { |
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| 98 | public: |
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| 99 | typedef T1 first_type; |
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| 100 | typedef T2 second_type; |
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| 101 | typedef typename call_traits<first_type>::param_type first_param_type; |
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| 102 | typedef typename call_traits<second_type>::param_type second_param_type; |
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| 103 | typedef typename call_traits<first_type>::reference first_reference; |
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| 104 | typedef typename call_traits<second_type>::reference second_reference; |
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| 105 | typedef typename call_traits<first_type>::const_reference first_const_reference; |
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| 106 | typedef typename call_traits<second_type>::const_reference second_const_reference; |
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| 107 | |
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| 108 | compressed_pair_imp() {} |
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| 109 | |
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| 110 | compressed_pair_imp(first_param_type x, second_param_type y) |
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| 111 | : first_(x), second_(y) {} |
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| 112 | |
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| 113 | compressed_pair_imp(first_param_type x) |
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| 114 | : first_(x) {} |
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| 115 | |
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| 116 | compressed_pair_imp(second_param_type y) |
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| 117 | : second_(y) {} |
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| 118 | |
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| 119 | first_reference first() {return first_;} |
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| 120 | first_const_reference first() const {return first_;} |
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| 121 | |
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| 122 | second_reference second() {return second_;} |
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| 123 | second_const_reference second() const {return second_;} |
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| 124 | |
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| 125 | void swap(::boost::compressed_pair<T1, T2>& y) |
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| 126 | { |
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| 127 | cp_swap(first_, y.first()); |
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| 128 | cp_swap(second_, y.second()); |
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| 129 | } |
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| 130 | private: |
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| 131 | first_type first_; |
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| 132 | second_type second_; |
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| 133 | }; |
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| 134 | |
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| 135 | // 1 derive from T1 |
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| 136 | |
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| 137 | template <class T1, class T2> |
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| 138 | class compressed_pair_imp<T1, T2, 1> |
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| 139 | : protected ::boost::remove_cv<T1>::type |
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| 140 | { |
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| 141 | public: |
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| 142 | typedef T1 first_type; |
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| 143 | typedef T2 second_type; |
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| 144 | typedef typename call_traits<first_type>::param_type first_param_type; |
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| 145 | typedef typename call_traits<second_type>::param_type second_param_type; |
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| 146 | typedef typename call_traits<first_type>::reference first_reference; |
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| 147 | typedef typename call_traits<second_type>::reference second_reference; |
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| 148 | typedef typename call_traits<first_type>::const_reference first_const_reference; |
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| 149 | typedef typename call_traits<second_type>::const_reference second_const_reference; |
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| 150 | |
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| 151 | compressed_pair_imp() {} |
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| 152 | |
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| 153 | compressed_pair_imp(first_param_type x, second_param_type y) |
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| 154 | : first_type(x), second_(y) {} |
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| 155 | |
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| 156 | compressed_pair_imp(first_param_type x) |
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| 157 | : first_type(x) {} |
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| 158 | |
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| 159 | compressed_pair_imp(second_param_type y) |
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| 160 | : second_(y) {} |
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| 161 | |
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| 162 | first_reference first() {return *this;} |
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| 163 | first_const_reference first() const {return *this;} |
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| 164 | |
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| 165 | second_reference second() {return second_;} |
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| 166 | second_const_reference second() const {return second_;} |
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| 167 | |
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| 168 | void swap(::boost::compressed_pair<T1,T2>& y) |
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| 169 | { |
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| 170 | // no need to swap empty base class: |
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| 171 | cp_swap(second_, y.second()); |
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| 172 | } |
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| 173 | private: |
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| 174 | second_type second_; |
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| 175 | }; |
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| 176 | |
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| 177 | // 2 derive from T2 |
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| 178 | |
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| 179 | template <class T1, class T2> |
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| 180 | class compressed_pair_imp<T1, T2, 2> |
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| 181 | : protected ::boost::remove_cv<T2>::type |
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| 182 | { |
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| 183 | public: |
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| 184 | typedef T1 first_type; |
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| 185 | typedef T2 second_type; |
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| 186 | typedef typename call_traits<first_type>::param_type first_param_type; |
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| 187 | typedef typename call_traits<second_type>::param_type second_param_type; |
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| 188 | typedef typename call_traits<first_type>::reference first_reference; |
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| 189 | typedef typename call_traits<second_type>::reference second_reference; |
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| 190 | typedef typename call_traits<first_type>::const_reference first_const_reference; |
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| 191 | typedef typename call_traits<second_type>::const_reference second_const_reference; |
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| 192 | |
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| 193 | compressed_pair_imp() {} |
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| 194 | |
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| 195 | compressed_pair_imp(first_param_type x, second_param_type y) |
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| 196 | : second_type(y), first_(x) {} |
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| 197 | |
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| 198 | compressed_pair_imp(first_param_type x) |
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| 199 | : first_(x) {} |
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| 200 | |
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| 201 | compressed_pair_imp(second_param_type y) |
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| 202 | : second_type(y) {} |
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| 203 | |
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| 204 | first_reference first() {return first_;} |
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| 205 | first_const_reference first() const {return first_;} |
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| 206 | |
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| 207 | second_reference second() {return *this;} |
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| 208 | second_const_reference second() const {return *this;} |
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| 209 | |
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| 210 | void swap(::boost::compressed_pair<T1,T2>& y) |
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| 211 | { |
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| 212 | // no need to swap empty base class: |
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| 213 | cp_swap(first_, y.first()); |
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| 214 | } |
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| 215 | |
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| 216 | private: |
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| 217 | first_type first_; |
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| 218 | }; |
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| 219 | |
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| 220 | // 3 derive from T1 and T2 |
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| 221 | |
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| 222 | template <class T1, class T2> |
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| 223 | class compressed_pair_imp<T1, T2, 3> |
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| 224 | : protected ::boost::remove_cv<T1>::type, |
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| 225 | protected ::boost::remove_cv<T2>::type |
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| 226 | { |
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| 227 | public: |
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| 228 | typedef T1 first_type; |
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| 229 | typedef T2 second_type; |
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| 230 | typedef typename call_traits<first_type>::param_type first_param_type; |
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| 231 | typedef typename call_traits<second_type>::param_type second_param_type; |
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| 232 | typedef typename call_traits<first_type>::reference first_reference; |
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| 233 | typedef typename call_traits<second_type>::reference second_reference; |
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| 234 | typedef typename call_traits<first_type>::const_reference first_const_reference; |
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| 235 | typedef typename call_traits<second_type>::const_reference second_const_reference; |
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| 236 | |
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| 237 | compressed_pair_imp() {} |
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| 238 | |
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| 239 | compressed_pair_imp(first_param_type x, second_param_type y) |
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| 240 | : first_type(x), second_type(y) {} |
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| 241 | |
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| 242 | compressed_pair_imp(first_param_type x) |
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| 243 | : first_type(x) {} |
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| 244 | |
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| 245 | compressed_pair_imp(second_param_type y) |
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| 246 | : second_type(y) {} |
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| 247 | |
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| 248 | first_reference first() {return *this;} |
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| 249 | first_const_reference first() const {return *this;} |
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| 250 | |
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| 251 | second_reference second() {return *this;} |
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| 252 | second_const_reference second() const {return *this;} |
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| 253 | // |
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| 254 | // no need to swap empty bases: |
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| 255 | void swap(::boost::compressed_pair<T1,T2>&) {} |
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| 256 | }; |
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| 257 | |
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| 258 | // JM |
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| 259 | // 4 T1 == T2, T1 and T2 both empty |
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| 260 | // Originally this did not store an instance of T2 at all |
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| 261 | // but that led to problems beause it meant &x.first() == &x.second() |
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| 262 | // which is not true for any other kind of pair, so now we store an instance |
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| 263 | // of T2 just in case the user is relying on first() and second() returning |
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| 264 | // different objects (albeit both empty). |
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| 265 | template <class T1, class T2> |
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| 266 | class compressed_pair_imp<T1, T2, 4> |
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| 267 | : protected ::boost::remove_cv<T1>::type |
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| 268 | { |
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| 269 | public: |
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| 270 | typedef T1 first_type; |
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| 271 | typedef T2 second_type; |
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| 272 | typedef typename call_traits<first_type>::param_type first_param_type; |
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| 273 | typedef typename call_traits<second_type>::param_type second_param_type; |
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| 274 | typedef typename call_traits<first_type>::reference first_reference; |
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| 275 | typedef typename call_traits<second_type>::reference second_reference; |
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| 276 | typedef typename call_traits<first_type>::const_reference first_const_reference; |
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| 277 | typedef typename call_traits<second_type>::const_reference second_const_reference; |
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| 278 | |
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| 279 | compressed_pair_imp() {} |
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| 280 | |
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| 281 | compressed_pair_imp(first_param_type x, second_param_type y) |
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| 282 | : first_type(x), m_second(y) {} |
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| 283 | |
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| 284 | compressed_pair_imp(first_param_type x) |
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| 285 | : first_type(x), m_second(x) {} |
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| 286 | |
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| 287 | first_reference first() {return *this;} |
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| 288 | first_const_reference first() const {return *this;} |
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| 289 | |
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| 290 | second_reference second() {return m_second;} |
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| 291 | second_const_reference second() const {return m_second;} |
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| 292 | |
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| 293 | void swap(::boost::compressed_pair<T1,T2>&) {} |
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| 294 | private: |
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| 295 | T2 m_second; |
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| 296 | }; |
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| 297 | |
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| 298 | // 5 T1 == T2 and are not empty: //JM |
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| 299 | |
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| 300 | template <class T1, class T2> |
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| 301 | class compressed_pair_imp<T1, T2, 5> |
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| 302 | { |
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| 303 | public: |
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| 304 | typedef T1 first_type; |
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| 305 | typedef T2 second_type; |
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| 306 | typedef typename call_traits<first_type>::param_type first_param_type; |
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| 307 | typedef typename call_traits<second_type>::param_type second_param_type; |
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| 308 | typedef typename call_traits<first_type>::reference first_reference; |
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| 309 | typedef typename call_traits<second_type>::reference second_reference; |
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| 310 | typedef typename call_traits<first_type>::const_reference first_const_reference; |
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| 311 | typedef typename call_traits<second_type>::const_reference second_const_reference; |
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| 312 | |
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| 313 | compressed_pair_imp() {} |
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| 314 | |
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| 315 | compressed_pair_imp(first_param_type x, second_param_type y) |
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| 316 | : first_(x), second_(y) {} |
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| 317 | |
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| 318 | compressed_pair_imp(first_param_type x) |
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| 319 | : first_(x), second_(x) {} |
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| 320 | |
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| 321 | first_reference first() {return first_;} |
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| 322 | first_const_reference first() const {return first_;} |
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| 323 | |
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| 324 | second_reference second() {return second_;} |
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| 325 | second_const_reference second() const {return second_;} |
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| 326 | |
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| 327 | void swap(::boost::compressed_pair<T1, T2>& y) |
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| 328 | { |
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| 329 | cp_swap(first_, y.first()); |
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| 330 | cp_swap(second_, y.second()); |
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| 331 | } |
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| 332 | private: |
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| 333 | first_type first_; |
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| 334 | second_type second_; |
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| 335 | }; |
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| 336 | |
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| 337 | } // details |
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| 338 | |
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| 339 | template <class T1, class T2> |
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| 340 | class compressed_pair |
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| 341 | : private ::boost::details::compressed_pair_imp<T1, T2, |
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| 342 | ::boost::details::compressed_pair_switch< |
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| 343 | T1, |
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| 344 | T2, |
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| 345 | ::boost::is_same<typename remove_cv<T1>::type, typename remove_cv<T2>::type>::value, |
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| 346 | ::boost::is_empty<T1>::value, |
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| 347 | ::boost::is_empty<T2>::value>::value> |
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| 348 | { |
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| 349 | private: |
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| 350 | typedef details::compressed_pair_imp<T1, T2, |
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| 351 | ::boost::details::compressed_pair_switch< |
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| 352 | T1, |
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| 353 | T2, |
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| 354 | ::boost::is_same<typename remove_cv<T1>::type, typename remove_cv<T2>::type>::value, |
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| 355 | ::boost::is_empty<T1>::value, |
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| 356 | ::boost::is_empty<T2>::value>::value> base; |
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| 357 | public: |
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| 358 | typedef T1 first_type; |
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| 359 | typedef T2 second_type; |
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| 360 | typedef typename call_traits<first_type>::param_type first_param_type; |
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| 361 | typedef typename call_traits<second_type>::param_type second_param_type; |
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| 362 | typedef typename call_traits<first_type>::reference first_reference; |
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| 363 | typedef typename call_traits<second_type>::reference second_reference; |
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| 364 | typedef typename call_traits<first_type>::const_reference first_const_reference; |
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| 365 | typedef typename call_traits<second_type>::const_reference second_const_reference; |
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| 366 | |
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| 367 | compressed_pair() : base() {} |
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| 368 | compressed_pair(first_param_type x, second_param_type y) : base(x, y) {} |
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| 369 | explicit compressed_pair(first_param_type x) : base(x) {} |
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| 370 | explicit compressed_pair(second_param_type y) : base(y) {} |
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| 371 | |
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| 372 | first_reference first() {return base::first();} |
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| 373 | first_const_reference first() const {return base::first();} |
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| 374 | |
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| 375 | second_reference second() {return base::second();} |
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| 376 | second_const_reference second() const {return base::second();} |
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| 377 | |
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| 378 | void swap(compressed_pair& y) { base::swap(y); } |
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| 379 | }; |
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| 380 | |
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| 381 | // JM |
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| 382 | // Partial specialisation for case where T1 == T2: |
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| 383 | // |
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| 384 | template <class T> |
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| 385 | class compressed_pair<T, T> |
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| 386 | : private details::compressed_pair_imp<T, T, |
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| 387 | ::boost::details::compressed_pair_switch< |
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| 388 | T, |
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| 389 | T, |
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| 390 | ::boost::is_same<typename remove_cv<T>::type, typename remove_cv<T>::type>::value, |
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| 391 | ::boost::is_empty<T>::value, |
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| 392 | ::boost::is_empty<T>::value>::value> |
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| 393 | { |
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| 394 | private: |
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| 395 | typedef details::compressed_pair_imp<T, T, |
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| 396 | ::boost::details::compressed_pair_switch< |
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| 397 | T, |
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| 398 | T, |
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| 399 | ::boost::is_same<typename remove_cv<T>::type, typename remove_cv<T>::type>::value, |
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| 400 | ::boost::is_empty<T>::value, |
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| 401 | ::boost::is_empty<T>::value>::value> base; |
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| 402 | public: |
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| 403 | typedef T first_type; |
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| 404 | typedef T second_type; |
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| 405 | typedef typename call_traits<first_type>::param_type first_param_type; |
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| 406 | typedef typename call_traits<second_type>::param_type second_param_type; |
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| 407 | typedef typename call_traits<first_type>::reference first_reference; |
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| 408 | typedef typename call_traits<second_type>::reference second_reference; |
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| 409 | typedef typename call_traits<first_type>::const_reference first_const_reference; |
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| 410 | typedef typename call_traits<second_type>::const_reference second_const_reference; |
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| 411 | |
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| 412 | compressed_pair() : base() {} |
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| 413 | compressed_pair(first_param_type x, second_param_type y) : base(x, y) {} |
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| 414 | #if !(defined(__SUNPRO_CC) && (__SUNPRO_CC <= 0x530)) |
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| 415 | explicit |
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| 416 | #endif |
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| 417 | compressed_pair(first_param_type x) : base(x) {} |
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| 418 | |
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| 419 | first_reference first() {return base::first();} |
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| 420 | first_const_reference first() const {return base::first();} |
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| 421 | |
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| 422 | second_reference second() {return base::second();} |
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| 423 | second_const_reference second() const {return base::second();} |
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| 424 | |
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| 425 | void swap(::boost::compressed_pair<T,T>& y) { base::swap(y); } |
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| 426 | }; |
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| 427 | |
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| 428 | template <class T1, class T2> |
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| 429 | inline |
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| 430 | void |
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| 431 | swap(compressed_pair<T1, T2>& x, compressed_pair<T1, T2>& y) |
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| 432 | { |
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| 433 | x.swap(y); |
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| 434 | } |
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| 435 | |
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| 436 | } // boost |
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| 437 | |
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| 438 | #ifdef BOOST_MSVC |
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| 439 | # pragma warning(pop) |
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| 440 | #endif |
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| 441 | |
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| 442 | #endif // BOOST_DETAIL_COMPRESSED_PAIR_HPP |
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| 443 | |
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