typedef QString::const_iterator qiter;

QString qtest = "sHello!";

qiter qbeg = qtest.begin();
qiter qend = qtest.end();

++qbeg;

???

typedef std::string::const_iterator iter;

std::string test = "sHello!";

iter beg = test.begin();
iter end = test.end();

++beg;

std::string str(beg, end); // str содержит в себе "Hello!"

QString qtest = "sHello!";

qiter qbeg = qtest.begin();
qiter qend = qtest.end();

++qbeg;

QString str;

for (; qbeg != qend; qbeg++) {
    str += *qbeg;
}

typedef QString::const_iterator qiter;

QString qtest = "sHello!";

qiter qbeg = qtest.begin();
qiter qend = qtest.end();

++qbeg;

QString str(qbeg, qend - qbeg);