std::codecvt<InternT,ExternT,StateT>::encoding, do_encoding

Since C++11

Header: <locale>

  1. Public member function, calls the member function do_encoding of the most derived class.

# Declarations

public:
int encoding() const throw();

(until C++11)

public:
int encoding() const noexcept;

(since C++11)

protected:
virtual int do_encoding() const throw();

(until C++11)

protected:
virtual int do_encoding() const noexcept;

(since C++11)

# Return value

The exact number of externT characters that correspond to one internT character, if constant. 0 if the number varies, -1 if the encoding is state-dependent.

# Example

#include <iostream>
#include <locale>
 
int main()
{
    std::cout << "en_US.utf8 is a variable-length encoding, encoding() returns "
              << std::use_facet<std::codecvt<wchar_t, char, std::mbstate_t>>(
                     std::locale("en_US.utf8")
                 ).encoding() << '\n';
 
    std::cout << "zh_CN.gb18030 is also variable-length, encoding() == "
              << std::use_facet<std::codecvt<wchar_t, char, std::mbstate_t>>(
                     std::locale("zh_CN.gb18030")
                 ).encoding() << '\n';
 
    std::cout << "ru_RU.koi8r is a single-byte encoding, encoding() == "
              << std::use_facet<std::codecvt<wchar_t, char, std::mbstate_t>>(
                     std::locale("ru_RU.koi8r")
                 ).encoding() << '\n';
}

# See also