Public Types | Public Member Functions | Related Functions

SparseMap< K, V, Comp > Class Template Reference


Detailed Description

template<typename K, typename V, typename Comp = std::less<K>>
class lemon::SparseMap< K, V, Comp >

This map is essentially a wrapper for std::map with addition that you can specify a default value for the keys that are not stored actually. This value can be different from the default contructed value (i.e. Value()). This type conforms to the ReferenceMap concept.

This map is useful if a default value should be assigned to most of the keys and different values should be assigned only to a few keys (i.e. the map is "sparse"). The name of this type also refers to this important usage.

Apart form that, this map can be used in many other cases since it is based on std::map, which is a general associative container. However, keep in mind that it is usually not as efficient as other maps.

The simplest way of using this map is through the sparseMap() function.

#include <lemon/maps.h>

Inheritance diagram for SparseMap< K, V, Comp >:

List of all members.

Public Types

typedef K Key
 Key type.
typedef V Value
 Value type.
typedef ValueReference
 Reference type.
typedef const ValueConstReference
 Const reference type.

Public Member Functions

 SparseMap (const Value &value=Value())
 Constructor with specified default value.
template<typename V1 , typename Comp1 >
 SparseMap (const std::map< Key, V1, Comp1 > &map, const Value &value=Value())
 Constructs the map from an appropriate std::map, and explicitly specifies a default value.
template<typename V1 , typename Comp1 >
 SparseMap (const SparseMap< Key, V1, Comp1 > &c)
 Constructs the map from another SparseMap.
Reference operator[] (const Key &k)
 
ConstReference operator[] (const Key &k) const
 
void set (const Key &k, const Value &v)
 
void setAll (const Value &v)
 

Related Functions

(Note that these are not member functions.)
template<typename K , typename V , typename Compare >
SparseMap< K, V, Compare > sparseMap (const V &value=V())
 Returns a SparseMap class.
template<typename K , typename V , typename Compare >
SparseMap< K, V, Compare > sparseMap (const std::map< K, V, Compare > &map, const V &value=V())
 Returns a SparseMap class created from an appropriate std::map.
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