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std::ranges::transform_view<V,F>::iterator

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Ranges library
Range access
Range conversions
(C++23)

Range primitives



Dangling iterator handling
Range concepts
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Range factories
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Range adaptor objects
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Helper items
(until C++23)(C++23)


 
 
template< bool Const >
class /*iterator*/
(since C++20)
(exposition only*)

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.

Contents

[edit] Member types

Member type Definition
Parent (private) const ranges::transform_view<V, F> if Const is true, otherwise ranges::transform_view<V, F>.
(exposition-only member type*)
Base (private) const V if Const is true, otherwise V.
(exposition-only member type*)
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 a reference, std::input_iterator_tag.

Else, let C be std::iterator_traits<ranges::iterator_t<Base>>::iterator_category. If C is std::contiguous_iterator_tag, the type is std::random_access_iterator_tag; otherwise, the type is C.

value_type std::remove_cvref_t<std::invoke_result_t<F&, ranges::range_reference_t<Base>>>
difference_type ranges::range_difference_t<Base>

[edit] Data members

Member object Definition
current_ (private) An iterator into (possibly const-qualified) V.
(exposition-only member object*)
parent_ (private) A pointer to parent transform_view.
(exposition-only member object*)

[edit] Member functions

constructs an iterator
(public member function)
(C++20)
returns the underlying iterator
(public member function)
(C++20)
accesses the transformed element
(public member function)
accesses an element by index
(public member function)
advances or decrements the underlying iterator
(public member function)

[edit] Non-member functions

compares the underlying iterators
(function)
performs iterator arithmetic
(function)
(C++20)
obtains an rvalue reference to the transformed element
(function)

[edit] 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
LWG 3798 C++20 iterator_category is input-only if transformation result is rvalue reference may have a stronger category