zypp::MapKVIteratorTraits< TMap > Struct Template Reference

Traits for std::map key and value iterators. More...

#include <zypp-core/base/Iterator.h>

Public Types
using	MapType = TMap
	The map type.
using	KeyType = typename TMap::key_type
	The maps key type.
using	Key_const_iterator = transform_iterator<GetPairFirst<typename MapType::value_type>, typename MapType::const_iterator>
	The key iterator type.
using	ValueType = typename TMap::mapped_type
	The maps value (mapped) type.
using	Value_const_iterator = transform_iterator<GetPairSecond<typename MapType::value_type>, typename MapType::const_iterator>
	The value iterator type.

Detailed Description

template<class TMap>
struct zypp::MapKVIteratorTraits< TMap >

Traits for std::map key and value iterators.

GetPairFirst and GetPairSecond help building a transform_iterator that iterates over keys or values of a std::map. Class MapKVIteratorTraits provides some typedefs, you usg. do not want to write explicitly.

// typedefs
typedef std::map<K,V> MapType;
 
// transform_iterator<GetPairFirst<MapType::value_type>,  MapType::const_iterator>
typedef MapKVIteratorTraits<MapType>::Key_const_iterator MapTypeKey_iterator;
// transform_iterator<GetPairSecond<MapType::value_type>, MapType::const_iterator>
typedef MapKVIteratorTraits<MapType>::Value_const_iterator  MapTypeValue_iterator;
 
// usage
MapType mymap;
 
MapTypeKey_const_iterator keyBegin( make_map_key_begin( mymap ) );
MapTypeKey_const_iterator keyEnd  ( make_map_key_end( mymap ) );
 
MapTypeValue_const_iterator valBegin( make_map_value_begin( mymap ) );
MapTypeValue_const_iterator valEnd  ( make_map_value_end( mymap ) );
 
std::for_each( keyBegin, keyEnd, DoSomething() );
std::for_each( valBegin, valEnd, DoSomething() );

Or short:

typedef std::map<K,V> MapType;
MapType mymap;
 
std::for_each( make_map_key_begin( mymap ),   make_map_key_end( mymap ),   DoSomething() );
std::for_each( make_map_value_begin( mymap ), make_map_value_end( mymap ), DoSomething() );

Definition at line 210 of file Iterator.h.

Member Typedef Documentation

MapType

template<class TMap>

using zypp::MapKVIteratorTraits< TMap >::MapType = TMap

The map type.

Definition at line 213 of file Iterator.h.

KeyType

template<class TMap>

using zypp::MapKVIteratorTraits< TMap >::KeyType = typename TMap::key_type

The maps key type.

Definition at line 215 of file Iterator.h.

Key_const_iterator

template<class TMap>

using zypp::MapKVIteratorTraits< TMap >::Key_const_iterator = transform_iterator<GetPairFirst<typename MapType::value_type>, typename MapType::const_iterator>

The key iterator type.

Definition at line 217 of file Iterator.h.

ValueType

template<class TMap>

using zypp::MapKVIteratorTraits< TMap >::ValueType = typename TMap::mapped_type

The maps value (mapped) type.

Definition at line 219 of file Iterator.h.

Value_const_iterator

template<class TMap>

using zypp::MapKVIteratorTraits< TMap >::Value_const_iterator = transform_iterator<GetPairSecond<typename MapType::value_type>, typename MapType::const_iterator>

The value iterator type.

Definition at line 221 of file Iterator.h.

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

• zypp-core/base/Iterator.h