std::codecvt<InternT,ExternT,StateT>:: max_length, do_max_length

Valor de retorno

El número máximo de ExternT caracteres que podrían consumirse si se convirtieran mediante in() para producir un InternT carácter.

La especialización no convertidora std:: codecvt < char , char , std:: mbstate_t > retorna 1 .

Notas

Si la codificación es dependiente del estado ( encoding ( ) == - 1 ), entonces pueden consumirse más de max_length() caracteres externos para producir un carácter interno.

Ejemplo

#include <codecvt>
#include <iostream>
#include <locale>
int main()
{
    std::cout << "In codecvt_utf8, the longest multibyte character is "
              << std::codecvt_utf8<wchar_t>().max_length() << " bytes long\n";
    std::cout << "In header-consuming codecvt_utf8, the longest multibyte character is "
              << std::codecvt_utf8<wchar_t,
                                   0x10ffff,
                                   std::consume_header>().max_length() << " bytes long\n";
    std::cout << "In this system's en_US.utf8, the longest multibyte character is "
              << std::use_facet<std::codecvt<wchar_t, char, std::mbstate_t>>(
                     std::locale("en_US.utf8")
                 ).max_length() << " bytes long\n";
    std::cout << "In this system's zh_CN.gb18030, the longest multibyte character is "
              << std::use_facet<std::codecvt<wchar_t, char, std::mbstate_t>>(
                     std::locale("zh_CN.gb18030")
                 ).max_length() << " bytes long\n";
}

In codecvt_utf8, the longest multibyte character is 4 bytes long
In header-consuming codecvt_utf8, the longest multibyte character is 7 bytes long
In this system's en_US.utf8, the longest multibyte character is 6 bytes long
In this system's zh_CN.gb18030, the longest multibyte character is 4 bytes long

Véase también