std::ranges::concat_view<Views...>:: iterator

Template parameters

Nested types

Determining the iterator concept

iterator_concept is defined as follows:

• If concat-is-random-access  < Const, Views... > is modeled, iterator_concept denotes std::random_access_iterator_tag .
• Otherwise, if concat-is-bidirectional  < Const, Views... > is modeled, iterator_concept denotes std::bidirectional_iterator_tag .
• Otherwise, if all-forward  < Const, Views... > is modeled, iterator_concept denotes std::forward_iterator_tag .
• Otherwise, iterator_concept denotes std::input_iterator_tag .

Determining the iterator category

iterator_category is defined if and only if all-forward  < Const, Views... > is modeled. In this case, it is defined as follows:

• If std:: is_reference_v < concat-reference-t  < maybe-const  < Const, Views > ... >> is false , iterator_category denotes std::input_iterator_tag .
• Otherwise, let Cs denote the pack of types std:: iterator_traits < ranges:: iterator_t < maybe-const  < Const, Views >>> :: iterator_category ... :
  • If ( std:: derived_from < Cs, std:: random_access_iterator_tag > && ... ) &&
    concat-is-random-access  < Const, Views... > is true , iterator_category denotes std::random_access_iterator_tag .
  • Otherwise, if ( std:: derived_from < Cs, std:: bidirectional_iterator_tag > && ... ) &&
    concat-is-bidirectional  < Const, Views... > is true , iterator_category denotes std::bidirectional_iterator_tag .
  • Otherwise, if ( std:: derived_from < Cs, std:: forward_iterator_tag > && ... ) is true , iterator_category denotes std::forward_iterator_tag .
  • Otherwise, iterator_category denotes std::input_iterator_tag .

Data members

Member functions

Non-member functions

Example

#include <iostream>
#include <iterator>
#include <ranges>
 
int main()
{
    namespace views = std::views;
    static constexpr int p[]{1, 2, 3};
    static constexpr auto e = {4, 5};
    auto t = views::iota(6, 9);
    auto cat = views::concat(p, e, t);
    auto dog = views::concat(cat, cat);
    for (auto i{dog.begin()}; i != std::default_sentinel; ++i)
        std::cout << *i << ' ';
    std::cout << '\n';
}

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References