std::codecvt_byname

Header: <locale>

std::codecvt_byname is a std::codecvt facet which encapsulates multibyte/wide character conversion rules of a locale specified at its construction.

# Declarations

template< class InternT, class ExternT, class State >
class codecvt_byname : public std::codecvt<InternT, ExternT, State>;

# Parameters

name: the name of the locale
refs: the number of references that link to the facet

# Example

#include <fstream>
#include <iostream>
#include <locale>
#include <string>
 
int main()
{
    // GB18030 narrow multibyte encoding
    std::ofstream("text.txt") << "\x7a"              // letter 'z', U+007a
                                 "\x81\x30\x89\x38"  // letter 'ß', U+00df
                                 "\xcb\xae"          // CJK ideogram '水' (water), U+6c34
                                 "\x94\x32\xbc\x35"; // musical sign '𝄋' (segno), U+1d10b
 
    std::wifstream fin("text.txt");
    fin.imbue(std::locale(fin.getloc(),
              new std::codecvt_byname<wchar_t, char, std::mbstate_t>("zh_CN.gb18030")));
 
    for (wchar_t c; fin.get(c);)
        std::cout << std::hex << std::showbase << static_cast<unsigned>(c) << '\n';
}

# Defect reports

DR	Applied to	Behavior as published	Correct behavior
LWG 21	C++98	the standard library did not need to provideany std::codecvt_byname specializations	two specializations are required

# See also

codecvt