join_view modelsinput_range.

join_view modelsforward_range when:

• ranges::range_reference_t<V> is a reference type, and
• V andranges::range_reference_t<V> each modelforward_range.

join_view modelsbidirectional_range when:

• ranges::range_reference_t<V> is a reference type,
• V modelsbidirectional_range, and
• ranges::range_reference_t<V> models bothbidirectional_range andcommon_range.

join_view modelscommon_range when:

• ranges::range_reference_t<V> is a reference type, and
• V andranges::range_reference_t<V> each modelforward_range andcommon_range.

[edit]Member functions

[edit]Deduction guides

[edit]Nested classes

[edit]Notes

BeforeP2328R1 was adopted, the inner range type (ranges::range_reference_t<V>) cannot be a container type (but can be reference to container). For example, it was not allowed to join atransform_view ofstd::string prvalue.

struct Person{int age;std::string name;}; auto f(std::vector<Person>& v){//  return v | std::views::transform([](auto& p){ return p.name; })//           | std::views::join; // error before P2328R1return v| std::views::transform([](auto& p)->std::string&{return p.name;})| std::views::join;// OK}

[edit]Example

#include <iostream>#include <ranges>#include <string_view>#include <vector> int main(){usingnamespace std::literals; constauto bits={"https:"sv,"//"sv,"cppreference"sv,"."sv,"com"sv};for(charconst c: bits| std::views::join)std::cout<< c;std::cout<<'\n'; conststd::vector<std::vector<int>> v{{1,2},{3,4,5},{6},{7,8,9}};auto jv= std::ranges::join_view(v);for(intconst e: jv)std::cout<< e<<' ';std::cout<<'\n';}

https://cppreference.com1 2 3 4 5 6 7 8 9

[edit]Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

[edit]See also

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