7        std::string    convertWStringToString(
const std::wstring &s);
 
    8        std::string    convertUTF16ToString(
const std::u16string &s);
 
    9        std::string    convertUTF32ToString(
const std::u32string &s);
 
   10        std::wstring   convertStringToWString(
const std::string &s);
 
   11        std::wstring   convertU16StringToWString(
const std::u16string &s);
 
   12        std::u16string convertStringToU16String(
const std::string &s);
 
   13        std::u16string convertStringToU16String(
const std::string_view &s);
 
   14        std::u16string convertWStringToU16String(
const std::wstring& s);
 
   15        std::u32string convertStringToU32String(
const std::string &s);
 
   16        unsigned convertUTF8CharToU16Char(
const char *begin,
const char *end,
char16_t *out);