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

#include <libosmscout/include/osmscout/FeatureReader.h>

Public Member Functions
	FeatureValueReader (const TypeConfig &typeConfig)
bool	GetIndex (const FeatureValueBuffer &buffer, size_t &index) const
V *	GetValue (const FeatureValueBuffer &buffer) const
V	GetValue (const FeatureValueBuffer &buffer, const V &defaultValue) const

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

buffer	The FeatureValueBuffer instance
index	The index

Returns

true, if there is a valid index (because the type has such feature), else false

GetValue() [1/2]

template<class F, class V>

V * osmscout::FeatureValueReader< F, V >::GetValue

(

const FeatureValueBuffer &

buffer

)

const

Returns the FeatureValue for the given FeatureValueBuffer

Parameters

buffer

The FeatureValueBuffer instance

Returns

A pointer to an instance if the Type and the instance do have the feature and its value is not nullptr, else nullptr

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

buffer

The FeatureValueBuffer instance

Returns

Either the value from the FeatureValueBuffer or the defaultValue

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

• libosmscout/include/osmscout/FeatureReader.h