libosmscout  0.1
osmscout::FeatureValueReader< F, V > Class Template Reference

Helper template class for easy access to the value of a certain feature for objects of any type. More...

#include <FeatureReader.h>

Public Member Functions

 FeatureValueReader (const TypeConfig &typeConfig)
 
bool GetIndex (const FeatureValueBuffer &buffer, size_t &index) const
 Returns the index of the Feature/FeatureValue within the given FeatureValueBuffer. More...
 
V * GetValue (const FeatureValueBuffer &buffer) const
 Returns the FeatureValue for the given FeatureValueBuffer. More...
 
GetValue (const FeatureValueBuffer &buffer, const V &defaultValue) const
 Returns the FeatureValue for the given FeatureValueBuffer or a defaultValue, if the feature is not set. More...
 

Detailed Description

template<class F, class V>
class osmscout::FeatureValueReader< F, V >

Helper template class for easy access to the value of a certain feature for objects of any type.

Each type may have stored the feature in request at a different index. The FeatureValueReader caches the index for each type once in the constructor and later on allows access to the feature value in O(1) - without iterating of all feature(values) of an object.

Constructor & Destructor Documentation

◆ FeatureValueReader()

template<class F , class V >
osmscout::FeatureValueReader< F, V >::FeatureValueReader ( const TypeConfig typeConfig)
explicit

Member Function Documentation

◆ GetIndex()

template<class F , class V >
bool osmscout::FeatureValueReader< F, V >::GetIndex ( const FeatureValueBuffer buffer,
size_t &  index 
) const

Returns the index of the Feature/FeatureValue within the given FeatureValueBuffer.

Parameters
bufferThe FeatureValueBuffer instance
indexThe index
Returns
true, if there is a valid index (because the type has such feature), else false

◆ GetValue() [1/2]

◆ GetValue() [2/2]

template<class F , class V >
V osmscout::FeatureValueReader< F, V >::GetValue ( const FeatureValueBuffer buffer,
const V &  defaultValue 
) const

Returns the FeatureValue for the given FeatureValueBuffer or a defaultValue, if the feature is not set.

Parameters
bufferThe FeatureValueBuffer instance
Returns
Either the value from the FeatureValueBuffer or the defaultValue

The documentation for this class was generated from the following file: