osmium::TagsFilterBase< TResult > Class Template Reference

#include <tags_filter.hpp>

Public Types
using	iterator = osmium::memory::CollectionFilterIterator< TagsFilterBase, const osmium::Tag >

Public Member Functions
	TagsFilterBase (const TResult default_result=TResult{})
void	set_default_result (const TResult default_result) noexcept
TagsFilterBase &	add_rule (const TResult result, const TagMatcher &matcher)
template<typename... TArgs>
TagsFilterBase &	add_rule (const TResult result, TArgs &&... args)
TResult	operator() (const osmium::Tag &tag) const noexcept
std::size_t	count () const noexcept
bool	empty () const noexcept

Private Attributes
std::vector< std::pair< TResult, TagMatcher > >	m_rules
TResult	m_default_result

Detailed Description

template<typename TResult>
class osmium::TagsFilterBase< TResult >

A TagsFilterBase is a list of rules (defined using TagMatchers) to check tags against. The first rule that matches sets the result.

Usually you want to use the TagsFilter class, which is simply a specialization with TResult=bool. But TResult can be any class that has a default constructor and a conversion to bool. The class should be small, because it is copied around in some places.

Here is an example matching any "highway" tag except "highway=motorway":

osmium::TagsFilter filter{false};
filter.add_rule(false, osmium::TagMatcher{"highway", "motorway"});
filter.add_rule(true, osmium::TagMatcher{"highway"});
 
osmium::Tag& tag = ...;
bool result = filter(tag);

Use this instead of the old osmium::tags::Filter.

Member Typedef Documentation

iterator

template<typename TResult >

using osmium::TagsFilterBase< TResult >::iterator = osmium::memory::CollectionFilterIterator<TagsFilterBase, const osmium::Tag>

Constructor & Destructor Documentation

TagsFilterBase()

template<typename TResult >

osmium::TagsFilterBase< TResult >::TagsFilterBase ( const TResult  default_result = TResult{} )

inlineexplicit

Constructor.

Parameters

default_result

The result the matching function will return if none of the rules matched.

Member Function Documentation

add_rule() [1/2]

template<typename TResult >

TagsFilterBase & osmium::TagsFilterBase< TResult >::add_rule ( const TResult  result, const TagMatcher &  matcher  )

inline

Add a rule to the filter.

Parameters

result	The result returned when this rule matches.
matcher	The TagMatcher for checking tags.

Returns

A reference to this filter for chaining.

add_rule() [2/2]

template<typename TResult >

template<typename... TArgs>

TagsFilterBase & osmium::TagsFilterBase< TResult >::add_rule ( const TResult  result, TArgs &&...  args  )

inline

Add a rule to the filter.

Parameters

result	The result returned when this rule matches.
args	Arguments to construct a TagMatcher from that is used for checking tags.

Returns

A reference to this filter for chaining.

count()

template<typename TResult >

std::size_t osmium::TagsFilterBase< TResult >::count ( ) const

inlinenoexcept

Return the number of rules in this filter.

Complexity: Constant.

empty()

template<typename TResult >

bool osmium::TagsFilterBase< TResult >::empty ( ) const

inlinenoexcept

Is this filter empty, ie are there no rules defined?

Complexity: Constant.

operator()()

template<typename TResult >

TResult osmium::TagsFilterBase< TResult >::operator() ( const osmium::Tag &  tag ) const

inlinenoexcept

Matching function. Check the specified tag against the rules.

Parameters

tag

A tag.

Returns

The result of the matching rule, or, if none of the rules matched, the default result.

set_default_result()

template<typename TResult >

void osmium::TagsFilterBase< TResult >::set_default_result ( const TResult  default_result )

inlinenoexcept

Set the default result, the result the matching function will return if none of the rules matched.

Member Data Documentation

m_default_result

template<typename TResult >

TResult osmium::TagsFilterBase< TResult >::m_default_result

private

m_rules

template<typename TResult >

std::vector<std::pair<TResult, TagMatcher> > osmium::TagsFilterBase< TResult >::m_rules

private

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

• include/osmium/tags/tags_filter.hpp