Visual Studio C ++ 2015 std :: codecvt com char16_t ou char32_t

Este código compilou OK no VS2013: std::string Unicode::utf16_to_utf8(std::u16string utf16_string) { std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t> convert; return convert.to_bytes(utf16_string); }Agora, com o VS2015, ...