std::ranges::join_with_view<V,Pattern>:: iterator

template < bool Const > class /*iterator*/		( exposition only* )

ranges:: join_with_view < V, Pattern > :: iterator is the type of the iterators returned by begin() and end() of ranges:: join_with_view < V, Pattern > .

The state of an iterator of this class is managed as if there are two nested iterators:

• an outer iterator into the parent range * parent_

• If Base models forward_range , it is outer_it_ .
• Otherwise, it is parent_  - > outer_it_ .

• an inner iterator inner_it_ into the pattern range parent_  - > pattern_ or into a child range of the parent range

This iterator class has the invariant that the inner iterator is always dereferenceable unless the outer iterator is not dereferenceable. When an iterator is constructed, incremented or decremented, its outer iterator might be adjusted to hold the invariant.

Contents 1 Template parameters 2 Nested types 2.1 Exposition-only types 2.2 Iterator property types 2.3 Determining the iterator concept 2.4 Determining the iterator category 3 Data members 4 Member functions 5 Non-member functions

Template parameters

Const

-

whether the iterator is a constant iterator

Nested types

Exposition-only types
Type	Definition
Parent	maybe-const  < Const, ranges:: join_with_view < V, Pattern >> ( exposition-only member type* )
Base	maybe-const  < Const, V > ( exposition-only member type* )
InnerBase	ranges:: range_reference_t < Base  > ( exposition-only member type* )
PatternBase	maybe-const  < Const, Pattern > ( exposition-only member type* )
OuterIter	ranges:: iterator_t < Base  > ( exposition-only member type* )
InnerIter	ranges:: iterator_t < InnerBase  > ( exposition-only member type* )
PatternIter	ranges:: iterator_t < PatternBase  > ( exposition-only member type* )
Iterator property types
Type	Definition
iterator_concept	an iterator tag , see below
iterator_category (conditionally present)	an iterator tag, see below
value_type	std:: common_type_t < ranges:: range_value_t < InnerBase  > , ranges:: range_value_t < PatternBase  >>
difference_type	std:: common_type_t < ranges:: range_difference_t < Base  > , ranges:: range_difference_t < InnerBase  > , ranges:: range_difference_t < PatternBase  >>

Determining the iterator concept

iterator_concept is defined as follows:

• If all following conditions are satisfied, iterator_concept denotes std::bidirectional_iterator_tag :
  • std:: is_reference_v < InnerBase  > is true .
  • Base models bidirectional_range .
  • InnerBase and PatternBase each model common_range .
• Otherwise, if all following conditions are satisfied, iterator_concept denotes std::forward_iterator_tag :
  • std:: is_reference_v < InnerBase  > is true .
  • Base and InnerBase each model forward_range .
• Otherwise, iterator_concept denotes std::input_iterator_tag .

Determining the iterator category

Given the following types:

• Let OuterC be std:: iterator_traits < OuterIter  > :: iterator_category .
• Let InnerC be std:: iterator_traits < InnerIter  > :: iterator_category .
• Let PatternC be std:: iterator_traits < PatternIter  > :: iterator_category .

iterator_category is defined if and only if std:: is_reference_v < InnerBase  > is true , and Base and InnerBase each model forward_range . In this case, it is defined as follows:

• If std:: is_reference_v < std:: common_reference_t < ranges:: range_reference_t < InnerBase  > ,
  ranges:: range_reference_t < PatternBase  >> is false , iterator_category denotes std::input_iterator_tag .
• Otherwise, if all following conditions are satisfied, iterator_category denotes std::bidirectional_iterator_tag :
  • OuterC , InnerC , and PatternC each model std:: derived_from < std:: bidirectional_iterator_tag > .
  • InnerBase and PatternBase each model common_range .
• Otherwise, if OuterC , InnerC , and PatternC each model std:: derived_from < std:: forward_iterator_tag > , iterator_category denotes std::forward_iterator_tag .
• Otherwise, iterator_category denotes std::input_iterator_tag .

Data members

Member	Description
Parent  * parent_	the pointer to the parent join_with_view ( exposition-only member object* )
OuterIter outer_it_ (present only if Base models forward_range )	the outer iterator ( exposition-only member object* )
std:: variant < PatternIter  , InnerIter  > inner_it_	the inner iterator ( exposition-only member object* )

Member functions

(constructor)	constructs an iterator (public member function)
operator*	accesses the element (public member function)
operator++ operator++ (int) operator-- operator-- (int)	advances or decrements the underlying iterator (public member function)

Non-member functions

operator== (C++23)	compares the underlying iterators (function)
iter_move (C++23)	casts the result of dereferencing the underlying iterator to its associated rvalue reference type (function)
iter_swap (C++23)	swaps the objects pointed to by two underlying iterators (function)