std::wcrtomb

`<cwchar>`
`std::size_t wcrtomb( char* s, wchar_t wc, std::mbstate_t* ps );`

.

s , , wc ( *ps) , s, *ps . MB_CUR_MAX .

s , std::wcrtomb(buf, L'\0', ps) buf .

wc L'\0', , , , *ps .

s		,
wc
ps		,

( ), , s.

( wc ), static_cast<std::size_t>(-1), EILSEQ errno *ps .

#include <clocale>
#include <cwchar>
#include <iostream>
#include <string>

void print_wide(const std::wstring& wstr)
{
    std::mbstate_t state{};
    for (wchar_t wc : wstr)
    {
        std::string mb(MB_CUR_MAX, '\0');
        std::size_t ret = std::wcrtomb(&mb[0], wc, &state);
        std::cout << "  " << mb << "  " << ret << " \n";
    }
}

int main()
{
    std::setlocale(LC_ALL, "en_US.utf8");
    std::wstring wstr = L"z\u00df\u6c34\U0001f34c"; //  L"z"
    print_wide(wstr);
}

:

wctomb	() []
mbrtowc	() []
do_out [virtual]	internT externT, , : converts a string from internT to externT, such as when writing to file Google. . . (virtual protected `std::codecvt` -) []
C wcrtomb







(C++20)

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





(C++20)


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

cppreference.com

std::wcrtomb