2 * src/lemon/maps.h - Part of LEMON, a generic C++ optimization library
4 * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
5 * (Egervary Combinatorial Optimization Research Group, EGRES).
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.
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
24 ///\brief Miscellaneous property maps
26 ///\todo This file has the same name as the concept file in concept/,
27 /// and this is not easily detectable in docs...
36 /// Base class of maps.
38 /// Base class of maps.
39 /// It provides the necessary <tt>typedef</tt>s required by the map concept.
40 template<typename K, typename T>
50 /// Null map. (a.k.a. DoNothingMap)
52 /// If you have to provide a map only for its type definitions,
53 /// or if you have to provide a writable map, but
54 /// data written to it will sent to <tt>/dev/null</tt>...
55 template<typename K, typename T>
56 class NullMap : public MapBase<K,T>
60 /// Gives back a default constructed element.
61 T operator[](const K&) const { return T(); }
62 /// Absorbs the value.
63 void set(const K&, const T&) {}
69 /// This is a readable map which assigns a specified value to each key.
70 /// In other aspects it is equivalent to the \ref NullMap.
71 /// \todo set could be used to set the value.
72 template<typename K, typename T>
73 class ConstMap : public MapBase<K,T>
78 /// Default constructor
80 /// The value of the map will be uninitialized.
81 /// (More exactly it will be default constructed.)
85 /// \param _v The initial value of the map.
87 ConstMap(const T &_v) : v(_v) {}
89 T operator[](const K&) const { return v; }
90 void set(const K&, const T&) {}
94 typedef ConstMap<K,T1> other;
98 ConstMap(const ConstMap<K,T1> &, const T &_v) : v(_v) {}
101 ///Returns a \ref ConstMap class
103 ///This function just returns a \ref ConstMap class.
105 template<class V,class K>
106 inline ConstMap<V,K> constMap(const K &k)
108 return ConstMap<V,K>(k);
113 template<typename T, T v>
116 template<typename K, typename V, V v>
117 class ConstMap<K, Const<V, v> > : public MapBase<K, V>
121 V operator[](const K&) const { return v; }
122 void set(const K&, const V&) { }
125 /// \c std::map wrapper
127 /// This is essentially a wrapper for \c std::map. With addition that
128 /// you can specify a default value different from \c Value() .
130 /// \todo Provide allocator parameter...
131 template <typename K, typename T, typename Compare = std::less<K> >
132 class StdMap : public std::map<K,T,Compare> {
133 typedef std::map<K,T,Compare> parent;
135 typedef typename parent::value_type PairType;
140 typedef T& Reference;
141 typedef const T& ConstReference;
145 /// Constructor with specified default value
146 StdMap(const T& _v) : v(_v) {}
148 /// \brief Constructs the map from an appropriate std::map.
150 /// \warning Inefficient: copies the content of \c m !
151 StdMap(const parent &m) : parent(m) {}
152 /// \brief Constructs the map from an appropriate std::map, and explicitly
153 /// specifies a default value.
155 /// \warning Inefficient: copies the content of \c m !
156 StdMap(const parent &m, const T& _v) : parent(m), v(_v) {}
158 template<typename T1, typename Comp1>
159 StdMap(const StdMap<Key,T1,Comp1> &m, const T &_v) {
163 Reference operator[](const Key &k) {
164 return insert(PairType(k,v)).first -> second;
166 ConstReference operator[](const Key &k) const {
167 typename parent::iterator i = lower_bound(k);
168 if (i == parent::end() || parent::key_comp()(k, (*i).first))
172 void set(const Key &k, const T &t) {
173 parent::operator[](k) = t;
176 /// Changes the default value of the map.
177 /// \return Returns the previous default value.
179 /// \warning The value of some keys (which has already been queried, but
180 /// the value has been unchanged from the default) may change!
181 T setDefault(const T &_v) { T old=v; v=_v; return old; }
183 template<typename T1>
185 typedef StdMap<Key,T1,Compare> other;
192 ///This \ref concept::ReadMap "read only map" returns the sum of the two
193 ///given maps. Its \c Key and \c Value will be inherited from \c M1.
194 ///The \c Key and \c Value of M2 must be convertible to those of \c M1.
196 template<class M1,class M2>
202 typedef typename M1::Key Key;
203 typedef typename M1::Value Value;
209 AddMap(const M1 &_m1,const M2 &_m2) : m1(_m1), m2(_m2) {};
210 Value operator[](Key k) const {return m1[k]+m2[k];}
213 ///Returns an \ref AddMap class
215 ///This function just returns an \ref AddMap class.
216 ///\todo How to call these type of functions?
219 ///\todo Wrong scope in Doxygen when \c \\relates is used
220 template<class M1,class M2>
221 inline AddMap<M1,M2> addMap(const M1 &m1,const M2 &m2)
223 return AddMap<M1,M2>(m1,m2);
226 ///Shift a maps with a constant.
228 ///This \ref concept::ReadMap "read only map" returns the sum of the
229 ///given map and a constant value.
230 ///Its \c Key and \c Value is inherited from \c M.
234 /// ShiftMap<X> sh(x,v);
236 ///it is equivalent with
238 /// ConstMap<X::Key, X::Value> c_tmp(v);
239 /// AddMap<X, ConstMap<X::Key, X::Value> > sh(x,v);
247 typedef typename M::Key Key;
248 typedef typename M::Value Value;
253 ///\param _m is the undelying map
254 ///\param _v is the shift value
255 ShiftMap(const M &_m,const Value &_v ) : m(_m), v(_v) {};
256 Value operator[](Key k) const {return m[k]+v;}
259 ///Returns an \ref ShiftMap class
261 ///This function just returns an \ref ShiftMap class.
263 ///\todo A better name is required.
265 inline ShiftMap<M> shiftMap(const M &m,const typename M::Value &v)
267 return ShiftMap<M>(m,v);
270 ///Difference of two maps
272 ///This \ref concept::ReadMap "read only map" returns the difference
273 ///of the values returned by the two
274 ///given maps. Its \c Key and \c Value will be inherited from \c M1.
275 ///The \c Key and \c Value of \c M2 must be convertible to those of \c M1.
277 template<class M1,class M2>
283 typedef typename M1::Key Key;
284 typedef typename M1::Value Value;
290 SubMap(const M1 &_m1,const M2 &_m2) : m1(_m1), m2(_m2) {};
291 Value operator[](Key k) const {return m1[k]-m2[k];}
294 ///Returns a \ref SubMap class
296 ///This function just returns a \ref SubMap class.
299 template<class M1,class M2>
300 inline SubMap<M1,M2> subMap(const M1 &m1,const M2 &m2)
302 return SubMap<M1,M2>(m1,m2);
305 ///Product of two maps
307 ///This \ref concept::ReadMap "read only map" returns the product of the
308 ///values returned by the two
310 ///maps. Its \c Key and \c Value will be inherited from \c M1.
311 ///The \c Key and \c Value of \c M2 must be convertible to those of \c M1.
313 template<class M1,class M2>
319 typedef typename M1::Key Key;
320 typedef typename M1::Value Value;
326 MulMap(const M1 &_m1,const M2 &_m2) : m1(_m1), m2(_m2) {};
327 Value operator[](Key k) const {return m1[k]*m2[k];}
330 ///Returns a \ref MulMap class
332 ///This function just returns a \ref MulMap class.
334 template<class M1,class M2>
335 inline MulMap<M1,M2> mulMap(const M1 &m1,const M2 &m2)
337 return MulMap<M1,M2>(m1,m2);
340 ///Scale a maps with a constant.
342 ///This \ref concept::ReadMap "read only map" returns the value of the
343 ///given map multipied with a constant value.
344 ///Its \c Key and \c Value is inherited from \c M.
348 /// ScaleMap<X> sc(x,v);
350 ///it is equivalent with
352 /// ConstMap<X::Key, X::Value> c_tmp(v);
353 /// MulMap<X, ConstMap<X::Key, X::Value> > sc(x,v);
361 typedef typename M::Key Key;
362 typedef typename M::Value Value;
367 ///\param _m is the undelying map
368 ///\param _v is the scaling value
369 ScaleMap(const M &_m,const Value &_v ) : m(_m), v(_v) {};
370 Value operator[](Key k) const {return m[k]*v;}
373 ///Returns an \ref ScaleMap class
375 ///This function just returns an \ref ScaleMap class.
377 ///\todo A better name is required.
379 inline ScaleMap<M> scaleMap(const M &m,const typename M::Value &v)
381 return ScaleMap<M>(m,v);
384 ///Quotient of two maps
386 ///This \ref concept::ReadMap "read only map" returns the quotient of the
387 ///values returned by the two
388 ///given maps. Its \c Key and \c Value will be inherited from \c M1.
389 ///The \c Key and \c Value of \c M2 must be convertible to those of \c M1.
391 template<class M1,class M2>
397 typedef typename M1::Key Key;
398 typedef typename M1::Value Value;
404 DivMap(const M1 &_m1,const M2 &_m2) : m1(_m1), m2(_m2) {};
405 Value operator[](Key k) const {return m1[k]/m2[k];}
408 ///Returns a \ref DivMap class
410 ///This function just returns a \ref DivMap class.
412 template<class M1,class M2>
413 inline DivMap<M1,M2> divMap(const M1 &m1,const M2 &m2)
415 return DivMap<M1,M2>(m1,m2);
418 ///Composition of two maps
420 ///This \ref concept::ReadMap "read only map" returns the composition of
422 ///given maps. That is to say, if \c m1 is of type \c M1 and \c m2 is
426 /// ComposeMap<M1,M2> cm(m1,m2);
428 /// <tt>cm[x]</tt> will be equal to <tt>m1[m2[x]]</tt>
430 ///Its \c Key is inherited from \c M2 and its \c Value is from
432 ///The \c M2::Value must be convertible to \c M1::Key.
433 ///\todo Check the requirements.
435 template<class M1,class M2>
441 typedef typename M2::Key Key;
442 typedef typename M1::Value Value;
448 ComposeMap(const M1 &_m1,const M2 &_m2) : m1(_m1), m2(_m2) {};
449 Value operator[](Key k) const {return m1[m2[k]];}
452 ///Returns a \ref ComposeMap class
454 ///This function just returns a \ref ComposeMap class.
455 ///\relates ComposeMap
456 template<class M1,class M2>
457 inline ComposeMap<M1,M2> composeMap(const M1 &m1,const M2 &m2)
459 return ComposeMap<M1,M2>(m1,m2);
462 ///Negative value of a map
464 ///This \ref concept::ReadMap "read only map" returns the negative
466 ///value returned by the
467 ///given map. Its \c Key and \c Value will be inherited from \c M.
468 ///The unary \c - operator must be defined for \c Value, of course.
475 typedef typename M::Key Key;
476 typedef typename M::Value Value;
482 NegMap(const M &_m) : m(_m) {};
483 Value operator[](Key k) const {return -m[k];}
486 ///Returns a \ref NegMap class
488 ///This function just returns a \ref NegMap class.
491 inline NegMap<M> negMap(const M &m)
497 ///Absolute value of a map
499 ///This \ref concept::ReadMap "read only map" returns the absolute value
501 ///value returned by the
502 ///given map. Its \c Key and \c Value will be inherited
503 ///from <tt>M</tt>. <tt>Value</tt>
504 ///must be comparable to <tt>0</tt> and the unary <tt>-</tt>
505 ///operator must be defined for it, of course.
507 ///\bug We need a unified way to handle the situation below:
509 /// struct _UnConvertible {};
510 /// template<class A> inline A t_abs(A a) {return _UnConvertible();}
511 /// template<> inline int t_abs<>(int n) {return abs(n);}
512 /// template<> inline long int t_abs<>(long int n) {return labs(n);}
513 /// template<> inline long long int t_abs<>(long long int n) {return ::llabs(n);}
514 /// template<> inline float t_abs<>(float n) {return fabsf(n);}
515 /// template<> inline double t_abs<>(double n) {return fabs(n);}
516 /// template<> inline long double t_abs<>(long double n) {return fabsl(n);}
525 typedef typename M::Key Key;
526 typedef typename M::Value Value;
532 AbsMap(const M &_m) : m(_m) {};
533 Value operator[](Key k) const {Value tmp=m[k]; return tmp>=0?tmp:-tmp;}
536 ///Returns a \ref AbsMap class
538 ///This function just returns a \ref AbsMap class.
541 inline AbsMap<M> absMap(const M &m)
546 ///Converts an STL style functor to a a map
548 ///This \ref concept::ReadMap "read only map" returns the value
552 ///Template parameters \c K and \c V will become its
553 ///\c Key and \c Value. They must be given explicitely
554 ///because a functor does not provide such typedefs.
556 ///Parameter \c F is the type of the used functor.
559 template<class K,class V,class F>
571 FunctorMap(const F &_f) : f(_f) {};
572 Value operator[](Key k) const {return f(k);}
575 ///Returns a \ref FunctorMap class
577 ///This function just returns a \ref FunctorMap class.
579 ///The third template parameter isn't necessary to be given.
580 ///\relates FunctorMap
581 template<class K,class V, class F>
582 inline FunctorMap<K,V,F> functorMap(const F &f)
584 return FunctorMap<K,V,F>(f);
587 ///Converts a map to an STL style functor
589 ///This class Converts a map to an STL style functor.
590 ///that is it provides an <tt>operator()</tt> to read its values.
592 ///For the sake of convenience it also works as a ususal map, i.e
593 ///<tt>operator[]</tt> and the \c Key and \c Valu typedefs also exist.
600 typedef typename M::Key Key;
601 typedef typename M::Value Value;
607 MapFunctor(const M &_m) : m(_m) {};
608 ///Returns a value of the map
612 Value operator()(Key k) const {return m[k];}
615 Value operator[](Key k) const {return m[k];}
618 ///Returns a \ref MapFunctor class
620 ///This function just returns a \ref MapFunctor class.
621 ///\relates MapFunctor
623 inline MapFunctor<M> mapFunctor(const M &m)
625 return MapFunctor<M>(m);
634 #endif // LEMON_MAPS_H