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

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< cpp‎ | string‎ | basic string

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

Returns a std::basic_string_view, constructed as if by std::basic_string_view<CharT, Traits>(data(), size()).

### Parameters

(none)

### Return value

A string view representing the entire contents of the string.

### Notes

It is the programmer's responsibility to ensure that the resulting string view does not outlive the string.

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

    int x = f(get_string()); // OK
    std::string_view sv = get_string(); // Bad: holds a dangling pointer

### Example

Run this code

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

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

    int main()
    {
        std::string cppstr = "ラーメン";   // narrow string
        std::wstring wcstr = L"ラーメン";  // wide string

        // Implicit conversion from string to string_view
        // via std::string::operator string_view:
        std::string_view cppstr_v = cppstr;

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

        // Implicit conversion from wstring to wstring_view
        // via std::wstring::operator wstring_view:
        show_wstring_size(wcstr);
    }

Output:

    ラーメン
    12 code units
    4 code points

### See also

(constructor) (C++17) | constructs a `basic_string_view` (public member function of `std::basic_string_view<CharT,Traits>`)

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