1 | /* -*- C++ -*- |
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2 | * src/lemon/maps.h - Part of LEMON, a generic C++ optimization library |
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3 | * |
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4 | * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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5 | * (Egervary Combinatorial Optimization Research Group, EGRES). |
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6 | * |
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7 | * Permission to use, modify and distribute this software is granted |
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8 | * provided that this copyright notice appears in all copies. For |
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9 | * precise terms see the accompanying LICENSE file. |
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10 | * |
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11 | * This software is provided "AS IS" with no warranty of any kind, |
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12 | * express or implied, and with no claim as to its suitability for any |
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13 | * purpose. |
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14 | * |
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15 | */ |
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16 | |
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17 | #ifndef LEMON_MAPS_H |
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18 | #define LEMON_MAPS_H |
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19 | |
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20 | ///\file |
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21 | ///\brief Miscellaneous property maps |
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22 | /// |
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23 | ///\todo This file has the same name as the concept file in concept/, |
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24 | /// and this is not easily detectable in docs... |
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25 | |
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26 | #include <map> |
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27 | |
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28 | namespace lemon { |
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29 | |
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30 | /// Base class of maps. |
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31 | |
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32 | /// Base class of maps. |
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33 | /// It provides the necessary <tt>typedef</tt>s required by the map concept. |
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34 | template<typename K, typename T> |
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35 | class MapBase |
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36 | { |
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37 | public: |
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38 | ///\e |
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39 | typedef K Key; |
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40 | ///\e |
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41 | typedef T Value; |
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42 | }; |
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43 | |
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44 | /// Null map. (a.k.a. DoNothingMap) |
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45 | |
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46 | /// If you have to provide a map only for its type definitions, |
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47 | /// or if you have to provide a writable map, but |
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48 | /// data written to it will sent to <tt>/dev/null</tt>... |
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49 | template<typename K, typename T> |
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50 | class NullMap : public MapBase<K,T> |
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51 | { |
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52 | public: |
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53 | |
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54 | /// Gives back a default constructed element. |
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55 | T operator[](const K&) const { return T(); } |
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56 | /// Absorbs the value. |
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57 | void set(const K&, const T&) {} |
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58 | }; |
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59 | |
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60 | |
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61 | /// Constant map. |
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62 | |
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63 | /// This is a readable map which assigns a specified value to each key. |
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64 | /// In other aspects it is equivalent to the \ref NullMap. |
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65 | /// \todo set could be used to set the value. |
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66 | template<typename K, typename T> |
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67 | class ConstMap : public MapBase<K,T> |
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68 | { |
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69 | T v; |
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70 | public: |
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71 | |
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72 | /// Default constructor |
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73 | |
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74 | /// The value of the map will be uninitialized. |
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75 | /// (More exactly it will be default constructed.) |
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76 | ConstMap() {} |
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77 | ///\e |
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78 | |
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79 | /// \param _v The initial value of the map. |
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80 | /// |
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81 | ConstMap(const T &_v) : v(_v) {} |
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82 | |
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83 | T operator[](const K&) const { return v; } |
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84 | void set(const K&, const T&) {} |
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85 | |
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86 | template<typename T1> |
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87 | struct rebind { |
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88 | typedef ConstMap<K,T1> other; |
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89 | }; |
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90 | |
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91 | template<typename T1> |
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92 | ConstMap(const ConstMap<K,T1> &, const T &_v) : v(_v) {} |
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93 | }; |
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94 | |
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95 | //to document later |
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96 | template<typename T, T v> |
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97 | struct Const { }; |
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98 | //to document later |
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99 | template<typename K, typename V, V v> |
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100 | class ConstMap<K, Const<V, v> > : public MapBase<K, V> |
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101 | { |
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102 | public: |
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103 | ConstMap() { } |
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104 | V operator[](const K&) const { return v; } |
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105 | void set(const K&, const V&) { } |
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106 | }; |
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107 | |
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108 | /// \c std::map wrapper |
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109 | |
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110 | /// This is essentially a wrapper for \c std::map. With addition that |
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111 | /// you can specify a default value different from \c Value() . |
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112 | /// |
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113 | /// \todo Provide allocator parameter... |
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114 | template <typename K, typename T, typename Compare = std::less<K> > |
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115 | class StdMap : public std::map<K,T,Compare> { |
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116 | typedef std::map<K,T,Compare> parent; |
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117 | T v; |
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118 | typedef typename parent::value_type PairType; |
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119 | |
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120 | public: |
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121 | typedef K Key; |
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122 | typedef T Value; |
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123 | typedef T& Reference; |
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124 | typedef const T& ConstReference; |
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125 | |
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126 | |
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127 | StdMap() : v() {} |
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128 | /// Constructor with specified default value |
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129 | StdMap(const T& _v) : v(_v) {} |
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130 | |
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131 | /// \brief Constructs the map from an appropriate std::map. |
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132 | /// |
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133 | /// \warning Inefficient: copies the content of \c m ! |
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134 | StdMap(const parent &m) : parent(m) {} |
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135 | /// \brief Constructs the map from an appropriate std::map, and explicitly |
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136 | /// specifies a default value. |
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137 | /// |
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138 | /// \warning Inefficient: copies the content of \c m ! |
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139 | StdMap(const parent &m, const T& _v) : parent(m), v(_v) {} |
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140 | |
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141 | template<typename T1, typename Comp1> |
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142 | StdMap(const StdMap<Key,T1,Comp1> &m, const T &_v) { |
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143 | //FIXME; |
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144 | } |
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145 | |
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146 | Reference operator[](const Key &k) { |
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147 | return insert(PairType(k,v)).first -> second; |
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148 | } |
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149 | ConstReference operator[](const Key &k) const { |
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150 | typename parent::iterator i = lower_bound(k); |
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151 | if (i == parent::end() || parent::key_comp()(k, (*i).first)) |
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152 | return v; |
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153 | return (*i).second; |
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154 | } |
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155 | void set(const Key &k, const T &t) { |
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156 | parent::operator[](k) = t; |
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157 | } |
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158 | |
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159 | /// Changes the default value of the map. |
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160 | /// \return Returns the previous default value. |
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161 | /// |
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162 | /// \warning The value of some keys (which has already been queried, but |
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163 | /// the value has been unchanged from the default) may change! |
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164 | T setDefault(const T &_v) { T old=v; v=_v; return old; } |
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165 | |
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166 | template<typename T1> |
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167 | struct rebind { |
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168 | typedef StdMap<Key,T1,Compare> other; |
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169 | }; |
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170 | }; |
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171 | |
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172 | } |
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173 | #endif // LEMON_MAPS_H |
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