This function provides a proper way of determining whether a function
returned by QMetaObject::method() is valid. (Checking whether
signature() returns a 0 pointer, which e.g. testlib does, is not an
ideal API -- especially given that signature() will soon be removed
and replaced by a function that returns a QByteArray.)
Change-Id: I644f476b09904925f2042945f5d0ad744482b682
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
5640b0b443