QTextStream::readLine() after >> with stdin

Question

I'm trying to read text with spaces from keyboard using object of QTextStream connected with stdin:

QTextStream cin(stdin, QIODevice::ReadOnly);

When I use >> it reads only till space.

QString str;
cin >> str; 

readLine() reads until end of the line

str = cin.readLine()

But when readLine() used after >> it just skips and doesn't do second read. I suppose it because after >> it remains in the same line which is now empty.

cin >> str; 
str = cin.readLine()

How can I force readLine() to perform second read? I can use empty readLine() to go to the next line, but maybe the are another solution?.

cin >> str; 
cin.readLine()
str = cin.readLine()