Qt 4.0.0 introduced a change to the way type names outside the current
scope were handled in signals and slots declarations and connections
which differed from the behavior in Qt 3.x.
Unfortunately, this could lead to signal-slot connections that were
potentially type-unsafe. Therefore, in Qt 4.0.1 type names must be fully
qualified in signal-slot declarations and connections.
For example, in Qt 4.0.0, it was possible to write:
connect(socket, SIGNAL(error(SocketError)), ...);
In Qt 4.0.1, the above connection must be made in the following way:
connect(socket, SIGNAL(error(QAbstractSocket::SocketError)), ...);
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