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std::ranges::views::join_with, std::ranges::join_with_view

Defined in header <ranges> 
template< ranges::input_range V, ranges::forward_range Pattern >
  requires ranges::view<V> and
           ranges::input_range<ranges::range_reference_t<V>> and
           ranges::view<Pattern> and
           /* ranges::range_reference_t<V> and Pattern
              have compatible elements (see below) */
class join_with_view : 
    ranges::view_interface<join_with_view<V, Pattern>>
 (1) (since C++23) 
namespace views {
    inline constexpr /* unspecified */ join_with = /* unspecified */;
}
 (2) (since C++23)
Call signature 
template< ranges::viewable_range R, class Pattern >
    requires /* see below */
constexpr ranges::view auto join_with( R&& r, Pattern&& pattern );
 (since C++23) 
template< class Pattern >
constexpr /* range adaptor closure */ join_with( Pattern&& pattern );
 (since C++23)
1) A range adaptor that represents view consisting of the sequence obtained from flattening a view of ranges, with every element of the delimiter inserted in between elements of the view. The delimiter can be a single element or a view of elements.
2) RangeAdaptorObject. The expression views::join_with(e, f) is expression-equivalent to join_with_view(e, f) for any suitable subexpressions e and f.

ranges::range_reference_t<V> and Pattern have compatible elements if all of the following concepts are modeled:

join_with_view models input_range.

join_with_view models forward_range when:

join_with_view models bidirectional_range when:

join_with_view models common_range when:

Member functions

(C++23)
 constructs a join_with_view
(public member function)
(C++23)
 returns a copy of the underlying (adapted) view
(public member function)
(C++23)
 returns an iterator to the beginning
(public member function)
(C++23)
 returns an iterator or a sentinel to the end
(public member function)
Inherited from std::ranges::view_interface
(C++20)
 returns whether the derived view is empty. Provided if it satisfies sized_range or forward_range.
(public member function of std::ranges::view_interface<D>)
(C++23)
 returns a constant iterator to the beginning of the range.
(public member function of std::ranges::view_interface<D>)
(C++23)
 returns a sentinel for the constant iterator of the range.
(public member function of std::ranges::view_interface<D>)
(C++20)
 returns whether the derived view is not empty. Provided if ranges::empty is applicable to it.
(public member function of std::ranges::view_interface<D>)
(C++20)
 returns the first element in the derived view. Provided if it satisfies forward_range.
(public member function of std::ranges::view_interface<D>)
(C++20)
 returns the last element in the derived view. Provided if it satisfies bidirectional_range and common_range.
(public member function of std::ranges::view_interface<D>)

Deduction guides

Nested classes

(C++23)
 the iterator type
(exposition-only member class template)
(C++23)
 the sentinel type
(exposition-only member class template)

Example

#include <iostream>
#include <ranges>
#include <string_view>
#include <vector>
 
int main()
{
    using namespace std::literals;
 
    std::vector v{"This"sv, "is"sv, "a"sv, "test."sv};
    auto joined = v | std::views::join_with(' ');
 
    for (auto c : joined)
        std::cout << c;
    std::cout << '\n';
}

Output:

This is a test.

See also

(C++20)
 a view consisting of the sequence obtained from flattening a view of ranges
(class template) (range adaptor object)

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