[1993] | 1 | /* -*- C++ -*- |
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| 2 | * |
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| 3 | * This file is a part of LEMON, a generic C++ optimization library |
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| 4 | * |
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| 5 | * Copyright (C) 2003-2006 |
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| 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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| 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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| 8 | * |
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| 9 | * Permission to use, modify and distribute this software is granted |
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| 10 | * provided that this copyright notice appears in all copies. For |
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| 11 | * precise terms see the accompanying LICENSE file. |
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| 12 | * |
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| 13 | * This software is provided "AS IS" with no warranty of any kind, |
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| 14 | * express or implied, and with no claim as to its suitability for any |
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| 15 | * purpose. |
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| 16 | * |
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| 17 | */ |
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| 18 | |
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| 19 | // This file contains a modified version of the enable_if library from BOOST. |
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| 20 | // See the appropriate copyright notice below. |
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| 21 | |
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| 22 | // Boost enable_if library |
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| 23 | |
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| 24 | // Copyright 2003 © The Trustees of Indiana University. |
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| 25 | |
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| 26 | // Use, modification, and distribution is subject to the Boost Software |
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| 27 | // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
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| 28 | // http://www.boost.org/LICENSE_1_0.txt) |
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| 29 | |
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| 30 | // Authors: Jaakko Järvi (jajarvi at osl.iu.edu) |
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| 31 | // Jeremiah Willcock (jewillco at osl.iu.edu) |
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| 32 | // Andrew Lumsdaine (lums at osl.iu.edu) |
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| 33 | |
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| 34 | |
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| 35 | #ifndef LEMON_BITS_UTILITY_H |
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| 36 | #define LEMON_BITS_UTILITY_H |
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| 37 | |
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[2077] | 38 | #include <lemon/error.h> |
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| 39 | |
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[1993] | 40 | ///\file |
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| 41 | ///\brief Miscellaneous basic utilities |
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| 42 | /// |
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| 43 | ///\todo Please rethink the organisation of the basic files like this. |
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| 44 | ///E.g. this file might be merged with invalid.h. |
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| 45 | |
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| 46 | |
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| 47 | namespace lemon |
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| 48 | { |
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| 49 | |
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| 50 | /// Basic type for defining "tags". A "YES" condition for \c enable_if. |
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| 51 | |
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| 52 | /// Basic type for defining "tags". A "YES" condition for \c enable_if. |
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| 53 | /// |
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| 54 | ///\sa False |
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| 55 | /// |
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| 56 | /// \todo This should go to a separate "basic_types.h" (or something) |
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| 57 | /// file. |
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| 58 | struct True { |
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| 59 | ///\e |
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| 60 | static const bool value = true; |
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| 61 | }; |
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| 62 | |
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| 63 | /// Basic type for defining "tags". A "NO" condition for \c enable_if. |
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| 64 | |
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| 65 | /// Basic type for defining "tags". A "NO" condition for \c enable_if. |
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| 66 | /// |
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| 67 | ///\sa True |
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| 68 | struct False { |
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| 69 | ///\e |
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| 70 | static const bool value = false; |
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| 71 | }; |
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| 72 | |
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| 73 | |
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| 74 | class InvalidType { |
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| 75 | private: |
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| 76 | InvalidType(); |
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| 77 | }; |
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[2077] | 78 | |
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| 79 | template <bool left, bool right> |
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| 80 | struct CTOr { |
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| 81 | static const bool value = true; |
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| 82 | }; |
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| 83 | |
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| 84 | template <> |
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| 85 | struct CTOr<false, false> { |
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| 86 | static const bool value = false; |
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| 87 | }; |
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| 88 | |
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| 89 | template <bool left, bool right> |
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| 90 | struct CTAnd { |
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| 91 | static const bool value = false; |
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| 92 | }; |
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| 93 | |
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| 94 | template <> |
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| 95 | struct CTAnd<true, true> { |
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| 96 | static const bool value = true; |
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| 97 | }; |
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| 98 | |
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| 99 | template <int left, int right> |
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| 100 | struct CTEqual { |
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| 101 | static const bool value = false; |
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| 102 | }; |
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| 103 | |
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| 104 | template <int val> |
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| 105 | struct CTEqual<val, val> { |
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| 106 | static const bool value = true; |
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| 107 | }; |
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| 108 | |
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| 109 | |
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| 110 | template <int left, int right> |
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| 111 | struct CTLess { |
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[2078] | 112 | static const bool value = left < right; |
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[2077] | 113 | }; |
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| 114 | |
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| 115 | template <int left> |
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| 116 | struct CTLess<left, 0> { |
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| 117 | static const bool value = false; |
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| 118 | }; |
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| 119 | |
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| 120 | template <int right> |
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| 121 | struct CTLess<0, right> { |
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| 122 | static const bool value = true; |
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| 123 | }; |
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| 124 | |
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| 125 | template <> |
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| 126 | struct CTLess<0, 0> { |
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| 127 | static const bool value = false; |
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| 128 | }; |
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| 129 | |
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| 130 | template <> |
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| 131 | struct CTLess<1, 1> { |
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| 132 | static const bool value = false; |
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| 133 | }; |
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| 134 | |
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| 135 | template <bool less, int left, int right> |
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| 136 | struct CTMaxImpl { |
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| 137 | static const int value = left; |
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| 138 | }; |
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| 139 | |
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| 140 | template <int left, int right> |
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| 141 | struct CTMaxImpl<true, left, right> { |
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| 142 | static const int value = right; |
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| 143 | }; |
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[1993] | 144 | |
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[2077] | 145 | template <int left, int right> |
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| 146 | struct CTMax { |
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| 147 | static const int value = |
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| 148 | CTMaxImpl<CTLess<left, right>::value, left, right>::value; |
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| 149 | }; |
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| 150 | |
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| 151 | |
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| 152 | /// \brief Simple Variant type with two type |
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| 153 | /// |
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| 154 | /// Simple Variant type with two type |
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| 155 | template <typename _First, typename _Second> |
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| 156 | class BiVariant { |
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| 157 | public: |
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| 158 | |
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| 159 | typedef _First First; |
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| 160 | typedef _Second Second; |
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| 161 | |
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| 162 | struct WrongStateError : public lemon::LogicError { |
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| 163 | public: |
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[2151] | 164 | virtual const char* what() const throw() { |
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[2077] | 165 | return "lemon::BiVariant::WrongStateError"; |
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| 166 | } |
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| 167 | }; |
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| 168 | |
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| 169 | BiVariant() { |
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| 170 | flag = true; |
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| 171 | new(reinterpret_cast<First*>(data)) First(); |
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| 172 | } |
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| 173 | |
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| 174 | BiVariant(const First& first) { |
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| 175 | flag = true; |
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| 176 | new(reinterpret_cast<First*>(data)) First(first); |
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| 177 | } |
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| 178 | |
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| 179 | BiVariant(const Second& second) { |
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| 180 | flag = false; |
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| 181 | new(reinterpret_cast<Second*>(data)) Second(second); |
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| 182 | } |
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| 183 | |
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| 184 | BiVariant(const BiVariant& bivariant) { |
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| 185 | flag = bivariant.flag; |
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| 186 | if (flag) { |
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| 187 | new(reinterpret_cast<First*>(data)) First(bivariant.first()); |
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| 188 | } else { |
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| 189 | new(reinterpret_cast<Second*>(data)) Second(bivariant.second()); |
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| 190 | } |
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| 191 | } |
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| 192 | |
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| 193 | ~BiVariant() { |
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| 194 | destroy(); |
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| 195 | } |
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| 196 | |
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| 197 | BiVariant& setFirst() { |
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| 198 | destroy(); |
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| 199 | flag = true; |
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| 200 | new(reinterpret_cast<First*>(data)) First(); |
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| 201 | return *this; |
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| 202 | } |
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| 203 | |
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| 204 | BiVariant& setFirst(const First& first) { |
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| 205 | destroy(); |
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| 206 | flag = true; |
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| 207 | new(reinterpret_cast<First*>(data)) First(first); |
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| 208 | return *this; |
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| 209 | } |
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| 210 | |
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| 211 | BiVariant& setSecond() { |
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| 212 | destroy(); |
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| 213 | flag = false; |
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| 214 | new(reinterpret_cast<Second*>(data)) Second(); |
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| 215 | return *this; |
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| 216 | } |
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| 217 | |
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| 218 | BiVariant& setSecond(const Second& second) { |
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| 219 | destroy(); |
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| 220 | flag = false; |
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| 221 | new(reinterpret_cast<Second*>(data)) Second(second); |
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| 222 | return *this; |
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| 223 | } |
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| 224 | |
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| 225 | BiVariant& operator=(const First& first) { |
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| 226 | return setFirst(first); |
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| 227 | } |
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| 228 | |
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| 229 | BiVariant& operator=(const Second& second) { |
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| 230 | return setSecond(second); |
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| 231 | } |
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| 232 | |
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| 233 | |
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| 234 | BiVariant& operator=(const BiVariant& bivariant) { |
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| 235 | if (this == &bivariant) return *this; |
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| 236 | destroy(); |
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| 237 | flag = bivariant.flag; |
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| 238 | if (flag) { |
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| 239 | new(reinterpret_cast<First*>(data)) First(bivariant.first()); |
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| 240 | } else { |
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| 241 | new(reinterpret_cast<Second*>(data)) Second(bivariant.second()); |
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| 242 | } |
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| 243 | return *this; |
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| 244 | } |
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| 245 | |
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| 246 | First& first() { |
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| 247 | LEMON_ASSERT(flag, WrongStateError()); |
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| 248 | return *reinterpret_cast<First*>(data); |
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| 249 | } |
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| 250 | |
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| 251 | const First& first() const { |
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| 252 | LEMON_ASSERT(flag, WrongStateError()); |
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| 253 | return *reinterpret_cast<const First*>(data); |
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| 254 | } |
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| 255 | |
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| 256 | operator First&() { return first(); } |
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| 257 | operator const First&() const { return first(); } |
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| 258 | |
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| 259 | Second& second() { |
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| 260 | LEMON_ASSERT(!flag, WrongStateError()); |
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| 261 | return *reinterpret_cast<Second*>(data); |
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| 262 | } |
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| 263 | |
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| 264 | const Second& second() const { |
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| 265 | LEMON_ASSERT(!flag, WrongStateError()); |
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| 266 | return *reinterpret_cast<const Second*>(data); |
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| 267 | } |
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| 268 | |
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| 269 | operator Second&() { return second(); } |
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| 270 | operator const Second&() const { return second(); } |
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| 271 | |
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| 272 | bool firstState() const { return flag; } |
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| 273 | bool secondState() const { return !flag; } |
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| 274 | |
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| 275 | private: |
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| 276 | |
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| 277 | void destroy() { |
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| 278 | if (flag) { |
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| 279 | reinterpret_cast<First*>(data)->~First(); |
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| 280 | } else { |
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| 281 | reinterpret_cast<Second*>(data)->~Second(); |
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| 282 | } |
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| 283 | } |
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| 284 | |
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| 285 | char data[CTMax<sizeof(First), sizeof(Second)>::value]; |
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| 286 | bool flag; |
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| 287 | }; |
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[1993] | 288 | |
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| 289 | template <typename T> |
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| 290 | struct Wrap { |
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| 291 | const T &value; |
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| 292 | Wrap(const T &t) : value(t) {} |
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| 293 | }; |
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| 294 | |
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| 295 | /**************** dummy class to avoid ambiguity ****************/ |
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| 296 | |
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| 297 | template<int T> struct dummy { dummy(int) {} }; |
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| 298 | |
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| 299 | /**************** enable_if from BOOST ****************/ |
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| 300 | |
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| 301 | template <bool B, class T = void> |
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| 302 | struct enable_if_c { |
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| 303 | typedef T type; |
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| 304 | }; |
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| 305 | |
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| 306 | template <class T> |
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| 307 | struct enable_if_c<false, T> {}; |
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| 308 | |
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| 309 | template <class Cond, class T = void> |
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| 310 | struct enable_if : public enable_if_c<Cond::value, T> {}; |
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| 311 | |
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| 312 | template <bool B, class T> |
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| 313 | struct lazy_enable_if_c { |
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| 314 | typedef typename T::type type; |
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| 315 | }; |
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| 316 | |
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| 317 | template <class T> |
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| 318 | struct lazy_enable_if_c<false, T> {}; |
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| 319 | |
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| 320 | template <class Cond, class T> |
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| 321 | struct lazy_enable_if : public lazy_enable_if_c<Cond::value, T> {}; |
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| 322 | |
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| 323 | |
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| 324 | template <bool B, class T = void> |
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| 325 | struct disable_if_c { |
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| 326 | typedef T type; |
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| 327 | }; |
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| 328 | |
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| 329 | template <class T> |
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| 330 | struct disable_if_c<true, T> {}; |
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| 331 | |
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| 332 | template <class Cond, class T = void> |
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| 333 | struct disable_if : public disable_if_c<Cond::value, T> {}; |
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| 334 | |
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| 335 | template <bool B, class T> |
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| 336 | struct lazy_disable_if_c { |
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| 337 | typedef typename T::type type; |
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| 338 | }; |
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| 339 | |
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| 340 | template <class T> |
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| 341 | struct lazy_disable_if_c<true, T> {}; |
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| 342 | |
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| 343 | template <class Cond, class T> |
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| 344 | struct lazy_disable_if : public lazy_disable_if_c<Cond::value, T> {}; |
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| 345 | |
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| 346 | } // namespace lemon |
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| 347 | |
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| 348 | #endif |
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