lemon/concepts/maps.h
author Alpar Juttner <alpar@cs.elte.hu>
Tue, 22 Jan 2008 16:03:41 +0000
changeset 86 eba5222bb6f5
parent 39 0a01d811071f
parent 48 93ae269876de
child 74 9394072da54f
permissions -rw-r--r--
Minor doc improvements
     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 
    59 	void constraints() {
    60 	  Value val = m[key];
    61 	  val = m[key];
    62 	  typename _ReadMap::Value own_val = m[own_key]; 
    63 	  own_val = m[own_key]; 
    64 
    65 	  ignore_unused_variable_warning(val);
    66 	  ignore_unused_variable_warning(own_val);
    67 	  ignore_unused_variable_warning(key);
    68 	}
    69 	Key& key;
    70 	typename _ReadMap::Key& own_key;
    71 	_ReadMap& m;
    72       };
    73       
    74     };
    75 
    76 
    77     /// Writable map concept
    78     
    79     /// Writable map concept.
    80     ///
    81     template<typename K, typename T>
    82     class WriteMap
    83     {
    84     public:
    85       /// The key type of the map.
    86       typedef K Key;    
    87       /// The value type of the map. (The type of objects associated with the keys).
    88       typedef T Value;
    89 
    90       /// Sets the value associated with a key.
    91       void set(const Key &,const Value &) {}
    92 
    93       ///Default constructor
    94       WriteMap() {}
    95 
    96       template <typename _WriteMap>
    97       struct Constraints {
    98 	void constraints() {
    99 	  // No constraints for constructor.
   100 	  m.set(key, val);
   101 	  m.set(own_key, own_val);
   102 	  ignore_unused_variable_warning(key);
   103 	  ignore_unused_variable_warning(val);
   104 	  ignore_unused_variable_warning(own_key);
   105 	  ignore_unused_variable_warning(own_val);
   106 	}
   107 
   108 	Value& val;
   109 	typename _WriteMap::Value own_val;
   110 	Key& key;
   111 	typename _WriteMap::Key& own_key;
   112 	_WriteMap& m;
   113 
   114       };
   115     };
   116 
   117     /// Read/writable map concept
   118     
   119     /// Read/writable map concept.
   120     ///
   121     template<typename K, typename T>
   122     class ReadWriteMap : public ReadMap<K,T>,
   123 			 public WriteMap<K,T>
   124     {
   125     public:
   126       /// The key type of the map.
   127       typedef K Key;    
   128       /// The value type of the map. (The type of objects associated with the keys).
   129       typedef T Value;
   130 
   131       /// Returns the value associated with a key.
   132       Value operator[](const Key &) const {return Value();}
   133       /// Sets the value associated with a key.
   134       void set(const Key & ,const Value &) {}
   135 
   136       template<typename _ReadWriteMap>
   137       struct Constraints {
   138 	void constraints() {
   139 	  checkConcept<ReadMap<K, T>, _ReadWriteMap >();
   140 	  checkConcept<WriteMap<K, T>, _ReadWriteMap >();
   141 	}
   142       };
   143     };
   144   
   145   
   146     /// Dereferable map concept
   147     
   148     /// Dereferable map concept.
   149     ///
   150     /// \todo Rethink this concept.
   151     template<typename K, typename T, typename R, typename CR>
   152     class ReferenceMap : public ReadWriteMap<K,T>
   153     {
   154     public:
   155       /// Tag for reference maps.
   156       typedef True ReferenceMapTag;
   157       /// The key type of the map.
   158       typedef K Key;    
   159       /// The value type of the map. (The type of objects associated with the keys).
   160       typedef T Value;
   161       /// The reference type of the map.
   162       typedef R Reference;
   163       /// The const reference type of the map.
   164       typedef CR ConstReference;
   165 
   166     protected:
   167       Value tmp;
   168     public:
   169 
   170       ///Returns a reference to the value associated with a key.
   171       Reference operator[](const Key &) { return tmp; }
   172       ///Returns a const reference to the value associated with a key.
   173       ConstReference operator[](const Key &) const { return tmp; }
   174       /// Sets the value associated with a key.
   175       void set(const Key &k,const Value &t) { operator[](k)=t; }
   176 
   177       template<typename _ReferenceMap>
   178       struct ReferenceMapConcept {
   179 
   180 	void constraints() {
   181 	  checkConcept<ReadWriteMap, _ReferenceMap >();
   182 	  m[key] = val;
   183 	  val  = m[key];
   184 	  m[key] = ref;
   185 	  ref = m[key];
   186 	  m[own_key] = own_val;
   187 	  own_val  = m[own_key];
   188 	  m[own_key] = own_ref;
   189 	  own_ref = m[own_key];	  	  
   190 	}
   191 
   192 	typename _ReferenceMap::Key& own_key;
   193 	typename _ReferenceMap::Value& own_val;
   194 	typename _ReferenceMap::Reference& own_ref;
   195 	Key& key;
   196 	Value& val;
   197 	Reference& ref;
   198 	_ReferenceMap& m;
   199       };
   200     };
   201 
   202     // @}
   203 
   204   } //namespace concepts
   205 
   206 } //namespace lemon
   207 
   208 #endif // LEMON_CONCEPT_MAPS_H