COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/maps.h @ 977:48962802d168

Last change on this file since 977:48962802d168 was 977:48962802d168, checked in by Mihaly Barasz, 15 years ago
  • enable_if imported from BOOST
  • count{Nodes,Edges} implemented via graph tags
  • some #include bugs fixed
File size: 4.7 KB
Line 
1/* -*- C++ -*-
2 * src/lemon/maps.h - Part of LEMON, a generic C++ optimization library
3 *
4 * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
5 * (Egervary Combinatorial Optimization Research Group, EGRES).
6 *
7 * Permission to use, modify and distribute this software is granted
8 * provided that this copyright notice appears in all copies. For
9 * precise terms see the accompanying LICENSE file.
10 *
11 * This software is provided "AS IS" with no warranty of any kind,
12 * express or implied, and with no claim as to its suitability for any
13 * purpose.
14 *
15 */
16
17#ifndef LEMON_MAPS_H
18#define LEMON_MAPS_H
19
20///\file
21///\brief Miscellaneous property maps
22///
23///\todo This file has the same name as the concept file in concept/,
24/// and this is not easily detectable in docs...
25
26#include <map>
27
28namespace lemon {
29
30  /// Base class of maps.
31
32  /// Base class of maps.
33  /// It provides the necessary <tt>typedef</tt>s required by the map concept.
34  template<typename K, typename T>
35  class MapBase
36  {
37  public:
38    ///\e
39    typedef K KeyType;
40    ///\e
41    typedef T ValueType;
42  };
43
44  /// Null map. (a.k.a. DoNothingMap)
45
46  /// If you have to provide a map only for its type definitions,
47  /// or if you have to provide a writable map, but
48  /// data written to it will sent to <tt>/dev/null</tt>...
49  template<typename K, typename T>
50  class NullMap : public MapBase<K,T>
51  {
52  public:
53
54    /// Gives back a default constructed element.
55    T operator[](const K&) const { return T(); }
56    /// Absorbs the value.
57    void set(const K&, const T&) {}
58  };
59
60
61  /// Constant map.
62
63  /// This is a readable map which assigns a specified value to each key.
64  /// In other aspects it is equivalent to the \ref NullMap.
65  /// \todo set could be used to set the value.
66  template<typename K, typename T>
67  class ConstMap : public MapBase<K,T>
68  {
69    T v;
70  public:
71
72    /// Default constructor
73
74    /// The value of the map will be uninitialized.
75    /// (More exactly it will be default constructed.)
76    ConstMap() {}
77    ///\e
78
79    /// \param _v The initial value of the map.
80    ///
81    ConstMap(const T &_v) : v(_v) {}
82
83    T operator[](const K&) const { return v; }
84    void set(const K&, const T&) {}
85
86    template<typename T1>
87    struct rebind {
88      typedef ConstMap<K,T1> other;
89    };
90
91    template<typename T1>
92    ConstMap(const ConstMap<K,T1> &, const T &_v) : v(_v) {}
93  };
94
95  //to document later
96  template<typename T, T v>
97  struct Const { };
98  //to document later
99  template<typename K, typename V, V v>
100  class ConstMap<K, Const<V, v> > : public MapBase<K, V>
101  {
102  public:
103    ConstMap() { }
104    V operator[](const K&) const { return v; }
105    void set(const K&, const V&) { }
106  };
107
108  /// \c std::map wrapper
109
110  /// This is essentially a wrapper for \c std::map. With addition that
111  /// you can specify a default value different from \c ValueType() .
112  ///
113  /// \todo Provide allocator parameter...
114  template <typename Key, typename T, typename Compare = std::less<Key> >
115  class StdMap : public std::map<Key,T,Compare> {
116    typedef std::map<Key,T,Compare> parent;
117    T v;
118    typedef typename parent::value_type PairType;
119
120  public:
121    typedef Key KeyType;
122    typedef T ValueType;
123    typedef T& ReferenceType;
124    typedef const T& ConstReferenceType;
125
126
127    StdMap() : v() {}
128    /// Constructor with specified default value
129    StdMap(const T& _v) : v(_v) {}
130
131    /// \brief Constructs the map from an appropriate std::map.
132    ///
133    /// \warning Inefficient: copies the content of \c m !
134    StdMap(const parent &m) : parent(m) {}
135    /// \brief Constructs the map from an appropriate std::map, and explicitly
136    /// specifies a default value.
137    ///
138    /// \warning Inefficient: copies the content of \c m !
139    StdMap(const parent &m, const T& _v) : parent(m), v(_v) {}
140   
141    template<typename T1, typename Comp1>
142    StdMap(const StdMap<Key,T1,Comp1> &m, const T &_v) {
143      //FIXME;
144    }
145
146    ReferenceType operator[](const Key &k) {
147      return insert(PairType(k,v)).first -> second;
148    }
149    ConstReferenceType operator[](const Key &k) const {
150      typename parent::iterator i = lower_bound(k);
151      if (i == parent::end() || parent::key_comp()(k, (*i).first))
152        return v;
153      return (*i).second;
154    }
155    void set(const Key &k, const T &t) {
156      parent::operator[](k) = t;
157    }
158
159    /// Changes the default value of the map.
160    /// \return Returns the previous default value.
161    ///
162    /// \warning The value of some keys (which has already been queried, but
163    /// the value has been unchanged from the default) may change!
164    T setDefault(const T &_v) { T old=v; v=_v; return old; }
165
166    template<typename T1>
167    struct rebind {
168      typedef StdMap<Key,T1,Compare> other;
169    };
170  };
171 
172}
173#endif // LEMON_MAPS_H
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