help using Glib::ustring

["Jamiil Abduqadir" <jalqadir gmail com>]

I am porting my old code to Gtkmm, I have started with the most fundamental of applications, a string manipulation class.
What I am trying to do is very simple, but the new paradigm has me a bit confused, to convert a string to upper case here is my code

const Glib::ustring& jme::strtools::toUpper( const Glib::ustring& s ) {
    //global variable
    tmp.clear();
    tmp = s;
    //remove non-printable characters
    tmp = this->trimIt( tmp );
    //Iterate through the string until the end of the is found 
    for ( Glib::ustring::iterator i = tmp.begin(); i != tmp.end(); ++i ) {
        *i = toupper( i ); <<=== the old version
    }
    return tmp;
}
i = i.uppercase()  ?? did not work
any suggestions?


Thanks folks
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