string - Converting QString to utf16 hex representation for non ascii characters -

i going convert qstring hex representation, works fine, until put special characters '€':

qstring l_str = "how you"; qdebug() << "hex:     " << l_str.toutf8().tohex(); qdebug() << "readable:" << l_str.toutf8(); 

prints out:

hex: "486f772061726520796f753f"

readable: "how you?"

and easy convert hex values ascii, being 2 values (48 = h etc.) hex representation of ascii char enough iterate , convert every 2 chars.

if set l_str = "h€w ar€ you?", , hex € sign in utf8 "e282ac" 6 values, result following:

hex: "48e282ac77206172e282ac20796f753f"

but how can readable string?

it better having conversion results in utf16 string:

hex: "0048006f20ac00200061007220ac00200079006f0075003f"

consider "ho€ ar€ you" string created @ runtime (so no qstringliteral available), , cannot use auto keyword.

you can convert string utf8/16, , convert buffer holds hexadecimal representation. these steps can followed in reverse order go hex utf8/16 string.

the toutf16hex function prepends byte order mark both little- , big-endian hosts can correctly decode utf16 representation.

// https://github.com/kubao/stackoverflown/tree/master/questions/str-to-utf-38831190 #include <qtcore>  qbytearray toutf8hex(const qstring & str) {    return str.toutf8().tohex(); } qstring fromutf8hex(const qbytearray & hex) {    return qstring::fromutf8(qbytearray::fromhex(hex)); }  qbytearray toutf16hex(qstring str) {    str.prepend(qchar::byteordermark);    // ok use `fromrawdata` since tohex copies it.    return qbytearray::fromrawdata(             reinterpret_cast<const char*>(str.constdata()), (str.size()+1)*2).tohex(); } qstring fromutf16hex(const qbytearray & hex) {    const qbytearray utf16 = qbytearray::fromhex(hex);    return qstring::fromutf16(reinterpret_cast<const quint16*>(utf16.data())); }  int main() {    const qstring str = qstringliteral("h€w ar€ you?");     // utf8 ,    const qbytearray hex8 = toutf8hex(str);    q_assert(fromutf8hex(hex8) == str);     // utf16 ,    const qbytearray hex16 = toutf16hex(str);    q_assert(fromutf16hex(hex16) == str); }