lemon/concepts/maps.h
author Alpar Juttner <alpar@cs.elte.hu>
Tue, 12 Feb 2008 21:03:19 +0000
changeset 75 6265aa2f9d7e
parent 51 90201bb15a8d
child 79 d73c2e8b25cb
permissions -rw-r--r--
Merge
     1 /* -*- C++ -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library
     4  *
     5  * Copyright (C) 2003-2008
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 #ifndef LEMON_CONCEPT_MAPS_H
    20 #define LEMON_CONCEPT_MAPS_H
    21 
    22 #include <lemon/bits/utility.h>
    23 #include <lemon/concept_check.h>
    24 
    25 ///\ingroup concept
    26 ///\file
    27 ///\brief Map concepts checking classes for testing and documenting.
    28 
    29 namespace lemon {
    30 
    31   namespace concepts {
    32   
    33     /// \addtogroup concept
    34     /// @{
    35 
    36     /// Readable map concept
    37 
    38     /// Readable map concept.
    39     ///
    40     template<typename K, typename T>
    41     class ReadMap
    42     {
    43     public:
    44       /// The key type of the map.
    45       typedef K Key;    
    46       /// The value type of the map. (The type of objects associated with the keys).
    47       typedef T Value;
    48 
    49       /// Returns the value associated with a key.
    50 
    51       /// Returns the value associated with a key.
    52       /// \bug Value shouldn't need to be default constructible.
    53       ///
    54       Value operator[](const Key &) const {return Value();}
    55 
    56       template<typename _ReadMap>
    57       struct Constraints {
    58 	void constraints() {
    59 	  Value val = m[key];
    60 	  val = m[key];
    61 	  typename _ReadMap::Value own_val = m[own_key]; 
    62 	  own_val = m[own_key]; 
    63 
    64 	  ignore_unused_variable_warning(val);
    65 	  ignore_unused_variable_warning(own_val);
    66 	  ignore_unused_variable_warning(key);
    67 	}
    68 	Key& key;
    69 	typename _ReadMap::Key& own_key;
    70 	_ReadMap& m;
    71       };
    72       
    73     };
    74 
    75 
    76     /// Writable map concept
    77     
    78     /// Writable map concept.
    79     ///
    80     template<typename K, typename T>
    81     class WriteMap
    82     {
    83     public:
    84       /// The key type of the map.
    85       typedef K Key;    
    86       /// The value type of the map. (The type of objects associated with the keys).
    87       typedef T Value;
    88 
    89       /// Sets the value associated with a key.
    90       void set(const Key &,const Value &) {}
    91 
    92       ///Default constructor
    93       WriteMap() {}
    94 
    95       template <typename _WriteMap>
    96       struct Constraints {
    97 	void constraints() {
    98 	  // No constraints for constructor.
    99 	  m.set(key, val);
   100 	  m.set(own_key, own_val);
   101 	  ignore_unused_variable_warning(key);
   102 	  ignore_unused_variable_warning(val);
   103 	  ignore_unused_variable_warning(own_key);
   104 	  ignore_unused_variable_warning(own_val);
   105 	}
   106 
   107 	Value& val;
   108 	typename _WriteMap::Value own_val;
   109 	Key& key;
   110 	typename _WriteMap::Key& own_key;
   111 	_WriteMap& m;
   112 
   113       };
   114     };
   115 
   116     /// Read/writable map concept
   117     
   118     /// Read/writable map concept.
   119     ///
   120     template<typename K, typename T>
   121     class ReadWriteMap : public ReadMap<K,T>,
   122 			 public WriteMap<K,T>
   123     {
   124     public:
   125       /// The key type of the map.
   126       typedef K Key;    
   127       /// The value type of the map. (The type of objects associated with the keys).
   128       typedef T Value;
   129 
   130       /// Returns the value associated with a key.
   131       Value operator[](const Key &) const {return Value();}
   132       /// Sets the value associated with a key.
   133       void set(const Key & ,const Value &) {}
   134 
   135       template<typename _ReadWriteMap>
   136       struct Constraints {
   137 	void constraints() {
   138 	  checkConcept<ReadMap<K, T>, _ReadWriteMap >();
   139 	  checkConcept<WriteMap<K, T>, _ReadWriteMap >();
   140 	}
   141       };
   142     };
   143   
   144   
   145     /// Dereferable map concept
   146     
   147     /// Dereferable map concept.
   148     ///
   149     /// \todo Rethink this concept.
   150     template<typename K, typename T, typename R, typename CR>
   151     class ReferenceMap : public ReadWriteMap<K,T>
   152     {
   153     public:
   154       /// Tag for reference maps.
   155       typedef True ReferenceMapTag;
   156       /// The key type of the map.
   157       typedef K Key;    
   158       /// The value type of the map. (The type of objects associated with the keys).
   159       typedef T Value;
   160       /// The reference type of the map.
   161       typedef R Reference;
   162       /// The const reference type of the map.
   163       typedef CR ConstReference;
   164 
   165     protected:
   166       Value tmp;
   167     public:
   168 
   169       ///Returns a reference to the value associated with a key.
   170       Reference operator[](const Key &) { return tmp; }
   171       ///Returns a const reference to the value associated with a key.
   172       ConstReference operator[](const Key &) const { return tmp; }
   173       /// Sets the value associated with a key.
   174       void set(const Key &k,const Value &t) { operator[](k)=t; }
   175 
   176       template<typename _ReferenceMap>
   177       struct Constraints {
   178 	void constraints() {
   179 	  checkConcept<ReadWriteMap<K, T>, _ReferenceMap >();
   180 	  m[key] = val;
   181 	  val  = m[key];
   182 	  m[key] = ref;
   183 	  ref = m[key];
   184 	  m[own_key] = own_val;
   185 	  own_val  = m[own_key];
   186 	  m[own_key] = own_ref;
   187 	  own_ref = m[own_key];	  	  
   188 	}
   189 
   190 	typename _ReferenceMap::Key& own_key;
   191 	typename _ReferenceMap::Value& own_val;
   192 	typename _ReferenceMap::Reference own_ref;
   193 	Key& key;
   194 	Value& val;
   195 	Reference ref;
   196 	_ReferenceMap& m;
   197       };
   198     };
   199 
   200     // @}
   201 
   202   } //namespace concepts
   203 
   204 } //namespace lemon
   205 
   206 #endif // LEMON_CONCEPT_MAPS_H