CrossRefMap< GR, K, V > Class Template Reference

Detailed Description

template<typename GR, typename K, typename V>
class lemon::CrossRefMap< GR, K, V >

This class provides simple invertable graph maps. It wraps a standard graph map (NodeMap, ArcMap or EdgeMap) and if a key is set to a new value, then stores it in the inverse map. The graph items can be accessed by their values either using InverseMap or operator()(), and the values of the map can be accessed with an STL compatible forward iterator (ValueIt).

This map is intended to be used when all associated values are different (the map is actually invertable) or there are only a few items with the same value. Otherwise consider to use IterableValueMap, which is more suitable and more efficient for such cases. It provides iterators to traverse the items with the same associated value, but it does not have InverseMap.

This type is not reference map, so it cannot be modified with the subscript operator.

Template Parameters

GR	The graph type.
K	The key type of the map (GR::Node, GR::Arc or GR::Edge).
V	The value type of the map.

See Also

IterableValueMap

#include <lemon/maps.h>

Inherits Type< GR, K >.

Classes
class	InverseMap
	The inverse map type of CrossRefMap. More...
class	ValueIt
	Forward iterator for values. More...

Public Types
typedef GR	Graph
	The graph type of CrossRefMap.
typedef K	Item
	The key type of CrossRefMap (Node, Arc or Edge).
typedef K	Key
	The key type of CrossRefMap (Node, Arc or Edge).
typedef V	Value
	The value type of CrossRefMap.
typedef ValueIt	ValueIterator
	Alias for ValueIt.

Public Member Functions
	CrossRefMap (const Graph &graph)
	Constructor.
ValueIt	beginValue () const
	Returns an iterator to the first value.
ValueIt	endValue () const
	Returns an iterator after the last value.
void	set (const Key &key, const Value &val)
MapTraits< Map >::ConstReturnValue	operator[] (const Key &key) const
Key	operator() (const Value &val) const
	Gives back an item by its value.
int	count (const Value &val) const
	Returns the number of items with the given value.
InverseMap	inverse () const
	Gives back the inverse of the map.

Protected Member Functions
virtual void	erase (const Key &key)
	Erase the key from the map and the inverse map.
virtual void	erase (const std::vector< Key > &keys)
	Erase more keys from the map and the inverse map.
virtual void	clear ()
	Clear the keys from the map and the inverse map.

Constructor & Destructor Documentation

CrossRefMap ( const Graph &  graph )

inlineexplicit

Construct a new CrossRefMap for the given graph.

Member Function Documentation

ValueIt beginValue ( ) const

inline

Returns an STL compatible iterator to the first value of the map. The values of the map can be accessed in the [beginValue, endValue) range.

ValueIt endValue ( ) const

inline

Returns an STL compatible iterator after the last value of the map. The values of the map can be accessed in the [beginValue, endValue) range.

void set ( const Key &  key, const Value &  val  )

inline

Sets the value associated with the given key.

MapTraits<Map>::ConstReturnValue operator[] ( const Key &  key ) const

inline

Returns the value associated with the given key.

Key operator() ( const Value &  val ) const

inline

This function gives back an item that is assigned to the given value or INVALID if no such item exists. If there are more items with the same associated value, only one of them is returned.

int count ( const Value &  val ) const

inline

This function returns the number of items with the given value associated with it.

virtual void erase ( const Key &  key )

inlineprotectedvirtual

Erase the key from the map and the inverse map. It is called by the AlterationNotifier.

virtual void erase ( const std::vector< Key > &  keys )

inlineprotectedvirtual

Erase more keys from the map and the inverse map. It is called by the AlterationNotifier.

virtual void clear ( )

inlineprotectedvirtual

Clear the keys from the map and the inverse map. It is called by the AlterationNotifier.

InverseMap inverse ( ) const

inline

Gives back the inverse of the CrossRefMap.