1 | // -*- C++ -*- // |
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2 | #ifndef HUGO_MAPS_H |
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3 | #define HUGO_MAPS_H |
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4 | |
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5 | ///\file |
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6 | ///\brief Miscellaneous property maps |
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7 | /// |
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8 | ///\todo This file has the same name as the concept file in skeletons, |
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9 | /// and this is not easily detectable in docs... |
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10 | |
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11 | #include <map> |
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12 | |
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13 | namespace hugo { |
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14 | |
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15 | /// Null map. (aka DoNothingMap) |
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16 | |
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17 | /// If you have to provide a map only for its type definitions, |
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18 | /// or if you have to provide a writable map, but will not use the |
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19 | /// data written to it... |
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20 | template<typename K, typename T> |
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21 | class NullMap |
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22 | { |
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23 | public: |
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24 | typedef K KeyType; |
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25 | typedef T ValueType; |
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26 | |
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27 | T operator[](const K&) const { return T(); } |
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28 | void set(const K&, const T&) {} |
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29 | }; |
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30 | |
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31 | |
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32 | /// Constant map. |
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33 | |
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34 | /// This is a readable map which assignes a specified value to each key. |
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35 | /// In other aspects it is equivalent to the \ref NullMap |
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36 | template<typename K, typename T> |
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37 | class ConstMap |
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38 | { |
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39 | T v; |
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40 | public: |
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41 | typedef K KeyType; |
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42 | typedef T ValueType; |
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43 | |
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44 | ConstMap() {} |
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45 | ConstMap(const T &_v) : v(_v) {} |
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46 | |
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47 | T operator[](const K&) const { return v; } |
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48 | void set(const K&, const T&) {} |
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49 | |
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50 | template<typename T1> |
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51 | struct rebind { |
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52 | typedef ConstMap<K,T1> other; |
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53 | }; |
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54 | |
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55 | template<typename T1> |
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56 | ConstMap(const ConstMap<K,T1> &, const T &_v) : v(_v) {} |
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57 | }; |
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58 | |
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59 | |
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60 | |
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61 | /// \c std::map wrapper |
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62 | |
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63 | /// This is essentially a wrapper for \c std::map. With addition that |
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64 | /// you can specify a default value different from \c ValueType() . |
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65 | /// |
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66 | /// \todo Provide allocator parameter... |
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67 | template <typename Key, typename T, typename Compare = std::less<Key> > |
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68 | class StdMap : public std::map<Key,T,Compare> { |
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69 | typedef std::map<Key,T,Compare> parent; |
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70 | T v; |
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71 | typedef typename parent::value_type PairType; |
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72 | |
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73 | public: |
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74 | typedef Key KeyType; |
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75 | typedef T ValueType; |
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76 | typedef T& ReferenceType; |
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77 | typedef const T& ConstReferenceType; |
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78 | |
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79 | |
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80 | StdMap() : v() {} |
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81 | /// Constructor with specified default value |
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82 | StdMap(const T& _v) : v(_v) {} |
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83 | |
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84 | /// \brief Constructs the map from an appropriate std::map. |
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85 | /// |
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86 | /// \warning Inefficient: copies the content of \c m ! |
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87 | StdMap(const parent &m) : parent(m) {} |
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88 | /// \brief Constructs the map from an appropriate std::map, and explicitly |
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89 | /// specifies a default value. |
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90 | /// |
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91 | /// \warning Inefficient: copies the content of \c m ! |
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92 | StdMap(const parent &m, const T& _v) : parent(m), v(_v) {} |
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93 | |
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94 | template<typename T1, typename Comp1> |
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95 | StdMap(const StdMap<Key,T1,Comp1> &m, const T &_v) { FIXME; } |
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96 | |
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97 | ReferenceType operator[](const Key &k) { |
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98 | return insert(PairType(k,v)).first -> second; |
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99 | } |
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100 | ConstReferenceType operator[](const Key &k) const { |
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101 | typename parent::iterator i = lower_bound(__k); |
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102 | if (i == end() || key_comp()(k, (*i).first)) |
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103 | return v; |
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104 | return (*i).second; |
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105 | } |
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106 | void set(const Key &k, const T &t) { |
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107 | parent::operator[](k) = t; |
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108 | } |
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109 | |
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110 | /// Changes the default value of the map. |
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111 | /// \return Returns the previous default value. |
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112 | /// |
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113 | /// \warning The value of some keys (which has alredy been queried, but |
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114 | /// the value has been unchanged from the default) may change! |
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115 | T setDefault(const T &_v) { T old=v; v=_v; return old; } |
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116 | |
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117 | template<typename T1> |
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118 | struct rebind { |
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119 | typedef StdMap<Key,T1,Compare> other; |
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120 | }; |
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121 | }; |
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122 | |
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123 | } |
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124 | #endif // HUGO_MAPS_H |
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