std::basic_string<CharT,Traits,Allocator>::operator basic_string_view

`operator std::basic_string_view<CharT, Traits>() const noexcept;`		( C++17) ( C++20)
`constexpr operator std::basic_string_view<CharT, Traits>() const noexcept;`		( C++20)

std::basic_string_view, std::basic_string_view<CharT, Traits>(data(), size()).

()

, .

, , .

std::string get_string();
int f(std::string_view sv);

int x = f(get_string()); // OK
std::string_view sv = get_string(); // :

#include <iostream>
#include <string>
#include <string_view>

void show_wstring_size(std::wstring_view wcstr_v)
{
    std::cout << wcstr_v.size() << "  \n";
}

int main()
{
    std::string cppstr = "";   //  
    std::wstring wcstr = L"";  //  

    //    string  string_view
    //  std::string::operator string_view:
    std::string_view cppstr_v = cppstr;

    std::cout << cppstr_v << '\n'
              << cppstr_v.size() << "  \n";

    //    wstring  wstring_view
    //  std::wstring::operator wstring_view:
    show_wstring_size(wcstr);
}

:


12  
4

()

(C++17)

basic_string_view
(public - std::basic_string_view<CharT,Traits>) []







(C++20)

(C++20)
(C++11)





(C++20)


/

(C++11)
(C++11)
(C++11)
(C++17)

cppreference.com

std::basic_string<CharT,Traits,Allocator>::operator basic_string_view