std::ranges::transform_view<V,F>::iterator
template< bool Const > class /*iterator*/ |
(since C++20) |
The return type of transform_view::begin, and of transform_view::end when the underlying view is a common_range.
The type /*iterator*/<true> is returned by the const-qualified overloads. The type /*iterator*/<false> is returned by the non-const-qualified overloads.
The name of this class template (shown here as iterator) is unspecified.
Typical implementation holds two data members: an iterator into (possibly const-qualified) V, and a pointer to parent transform_view.
Member types
| Member type | Definition |
|---|---|
Parent (private) |
const ranges::transform_view<V, F> if Const is true, otherwise ranges::transform_view<V, F>. The name is for exposition only. |
Base (private) |
const V if Const is true, otherwise V. The name is for exposition only. |
iterator_concept |
std::random_access_iterator_tag if Base models random_access_range,std::bidirectional_iterator_tag if Base models bidirectional_range,std::forward_iterator_tag if Base models forward_range,std::input_iterator_tag otherwise. |
iterator_category |
Not defined if Base does not model forward_range.Otherwise, if std::invoke_result_t<F&, ranges::range_reference_t<Base>> is not an lvalue reference, std::input_iterator_tag.Else, let |
value_type |
std::remove_cvref_t<std::invoke_result_t<F&, ranges::range_reference_t<Base>>> |
difference_type |
ranges::range_difference_t<Base> |
Member functions
|
(C++20)
|
constructs an iterator (public member function) |
|
(C++20)
|
returns the underlying iterator (public member function) |
|
(C++20)
|
accesses the transformed element (public member function) |
|
(C++20)
|
accesses an element by index (public member function) |
|
(C++20)
|
advances or decrements the underlying iterator (public member function) |
Non-member functions
|
(C++20)
|
compares the underlying iterators (function) |
|
(C++20)
|
performs iterator arithmetic (function) |
|
(C++20)
|
obtains an rvalue reference to the transformed element (function) |
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| P2259R1 | C++20 | member iterator_category is always defined |
defined only if Base models forward_range |
| LWG 3555 | C++20 | the definition of iterator_concept ignores const |
made to consider |
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