Encoding Conversion for C++ (deprecated in C++17).

0_gbk2utf8.cpp

#include <codecvt>
std::string name = "李研"; // GBK encoding

std::wstring w_name = string2wstring(name, ".936");
std::string utf8_name = wstring2utf8(w_name);

1_wstring2utf8.cpp

std::string wstring2utf8(const std::wstring & wstr) {
	std::wstring_convert< std::codecvt_utf8<wchar_t> > cnv;
	return cnv.to_bytes(wstr);
}

2_utf82wstring.cpp

std::wstring utf82wstring(const std::string & str) {
	std::wstring_convert< std::codecvt_utf8<wchar_t> > cnv;
	return cnv.from_bytes(str);
}

3_wstring2string.cpp

std::string wstring2string(const std::wstring & wstr, const std::string & locale) {
	typedef std::codecvt_byname<wchar_t, char, std::mbstate_t> F;
	std::wstring_convert<F> cnv(new F(locale));
	return cnv.to_bytes(wstr);
}

4_string2wstring.cpp

std::wstring string2wstring(const std::string & str, const std::string & locale) {
	typedef std::codecvt_byname<wchar_t, char, std::mbstate_t> F;
	std::wstring_convert<F> cnv(new F(locale));
	return cnv.from_bytes(str);
}