我尝试重载operator在Qt中。classMyCryptographicHash:publicQCryptographicHash{public:MyCryptographicHash(Algorithmmethod);voidaddData(constQString&data);friendMyCryptographicHash&operatoraddData("abc1234");QStringa;a="qweer321";hash2result();qDebug()result();}但是我得到错误:nomatchfor'operator我试图将运算符声明为类的成员，但也出现