lemon/concepts/maps.h
author Alpar Juttner <alpar@cs.elte.hu>
Wed, 29 Jul 2020 14:56:10 +0200
changeset 1433 a278d16bd2d0
parent 1270 dceba191c00d
permissions -rw-r--r--
Fix clang compilation issue (#634)
     1 /* -*- mode: C++; indent-tabs-mode: nil; -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library.
     4  *
     5  * Copyright (C) 2003-2013
     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_CONCEPTS_MAPS_H
    20 #define LEMON_CONCEPTS_MAPS_H
    21 
    22 #include <lemon/core.h>
    23 #include <lemon/concept_check.h>
    24 
    25 ///\ingroup map_concepts
    26 ///\file
    27 ///\brief The concept of maps.
    28 
    29 namespace lemon {
    30 
    31   namespace concepts {
    32 
    33     /// \addtogroup map_concepts
    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       /// \brief The value type of the map.
    47       /// (The type of objects associated with the keys).
    48       typedef T Value;
    49 
    50       /// Returns the value associated with the given key.
    51       Value operator[](const Key &) const {
    52         // return *(static_cast<Value *>(0));
    53         // return *(static_cast<Value *>(0)+1);
    54         // return *(static_cast<Value *>(sizeof(Value)));
    55         // return *(reinterpret_cast<Value *>(0));
    56         // return *(reinterpret_cast<Value *>(0)+1);
    57         return *(reinterpret_cast<Value *>(sizeof(Value)));
    58       }
    59 
    60       template<typename _ReadMap>
    61       struct Constraints {
    62         void constraints() {
    63           Value val = m[key];
    64           val = m[key];
    65           typename _ReadMap::Value own_val = m[own_key];
    66           own_val = m[own_key];
    67 
    68           ::lemon::ignore_unused_variable_warning(key);
    69           ::lemon::ignore_unused_variable_warning(val);
    70           ::lemon::ignore_unused_variable_warning(own_key);
    71           ::lemon::ignore_unused_variable_warning(own_val);
    72         }
    73         const Key& key;
    74         const typename _ReadMap::Key& own_key;
    75         const _ReadMap& m;
    76         Constraints() {}
    77       };
    78 
    79     };
    80 
    81 
    82     /// Writable map concept
    83 
    84     /// Writable map concept.
    85     ///
    86     template<typename K, typename T>
    87     class WriteMap
    88     {
    89     public:
    90       /// The key type of the map.
    91       typedef K Key;
    92       /// \brief The value type of the map.
    93       /// (The type of objects associated with the keys).
    94       typedef T Value;
    95 
    96       /// Sets the value associated with the given key.
    97       void set(const Key &, const Value &) {}
    98 
    99       /// Default constructor.
   100       WriteMap() {}
   101 
   102       template <typename _WriteMap>
   103       struct Constraints {
   104         void constraints() {
   105           m.set(key, val);
   106           m.set(own_key, own_val);
   107 
   108           ::lemon::ignore_unused_variable_warning(key);
   109           ::lemon::ignore_unused_variable_warning(val);
   110           ::lemon::ignore_unused_variable_warning(own_key);
   111           ::lemon::ignore_unused_variable_warning(own_val);
   112         }
   113         const Key& key;
   114         const Value& val;
   115         const typename _WriteMap::Key& own_key;
   116         const typename _WriteMap::Value& own_val;
   117         _WriteMap& m;
   118         Constraints() {}
   119       };
   120     };
   121 
   122     /// Read/writable map concept
   123 
   124     /// Read/writable map concept.
   125     ///
   126     template<typename K, typename T>
   127     class ReadWriteMap : public ReadMap<K,T>,
   128                          public WriteMap<K,T>
   129     {
   130     public:
   131       /// The key type of the map.
   132       typedef K Key;
   133       /// \brief The value type of the map.
   134       /// (The type of objects associated with the keys).
   135       typedef T Value;
   136 
   137       /// Returns the value associated with the given key.
   138       Value operator[](const Key &) const {
   139         return *(reinterpret_cast<Value *>(sizeof(Value)));
   140       }
   141 
   142       /// Sets the value associated with the given key.
   143       void set(const Key &, const Value &) {}
   144 
   145       template<typename _ReadWriteMap>
   146       struct Constraints {
   147         void constraints() {
   148           checkConcept<ReadMap<K, T>, _ReadWriteMap >();
   149           checkConcept<WriteMap<K, T>, _ReadWriteMap >();
   150         }
   151       };
   152     };
   153 
   154 
   155     /// Dereferable map concept
   156 
   157     /// Dereferable map concept.
   158     ///
   159     template<typename K, typename T, typename R, typename CR>
   160     class ReferenceMap : public ReadWriteMap<K,T>
   161     {
   162     public:
   163       /// Tag for reference maps.
   164       typedef True ReferenceMapTag;
   165       /// The key type of the map.
   166       typedef K Key;
   167       /// \brief The value type of the map.
   168       /// (The type of objects associated with the keys).
   169       typedef T Value;
   170       /// The reference type of the map.
   171       typedef R Reference;
   172       /// The const reference type of the map.
   173       typedef CR ConstReference;
   174 
   175     public:
   176 
   177       /// Returns a reference to the value associated with the given key.
   178       Reference operator[](const Key &) {
   179         return *(reinterpret_cast<Value *>(sizeof(Value)));
   180       }
   181 
   182       /// Returns a const reference to the value associated with the given key.
   183       ConstReference operator[](const Key &) const {
   184         return *(reinterpret_cast<Value *>(sizeof(Value)));
   185       }
   186 
   187       /// Sets the value associated with the given key.
   188       void set(const Key &k,const Value &t) { operator[](k)=t; }
   189 
   190       template<typename _ReferenceMap>
   191       struct Constraints {
   192         typename enable_if<typename _ReferenceMap::ReferenceMapTag, void>::type
   193         constraints() {
   194           checkConcept<ReadWriteMap<K, T>, _ReferenceMap >();
   195           ref = m[key];
   196           m[key] = val;
   197           m[key] = ref;
   198           m[key] = cref;
   199           own_ref = m[own_key];
   200           m[own_key] = own_val;
   201           m[own_key] = own_ref;
   202           m[own_key] = own_cref;
   203           m[key] = m[own_key];
   204           m[own_key] = m[key];
   205         }
   206         const Key& key;
   207         Value& val;
   208         Reference ref;
   209         ConstReference cref;
   210         const typename _ReferenceMap::Key& own_key;
   211         typename _ReferenceMap::Value& own_val;
   212         typename _ReferenceMap::Reference own_ref;
   213         typename _ReferenceMap::ConstReference own_cref;
   214         _ReferenceMap& m;
   215         Constraints() {}
   216       };
   217     };
   218 
   219     // @}
   220 
   221   } //namespace concepts
   222 
   223 } //namespace lemon
   224 
   225 #endif