Under some circumstances, MSVC seems to complain about SlotArgumentCount
being unused
qobject.h(210): warning C4189: 'SlotArgumentCount': local variable is
initialized but not referenced
note: see reference to function template instantiation
'QMetaObject::Connection QObject::connect<void(__cdecl QAction::* )(bool),
main::<lambda_1>>(const QAction *,Func1,
const QtPrivate::ContextTypeForFunctor<main::<lambda_1>,void>::ContextType *,
Func2 &&,Qt::ConnectionType)' being compiled
This is nonsense, as SlotArgumentCount is used in the next line, to
construct the list of signal arguments, but the workaround to declare
the variable as [[maybe_unused]] is trivial.
Add a connect statement to the test case that creates such a connection.
This does not produce any warning with or without the attribute (and if
it did, the build would fail for CI configuratinos setting -Werror).
Pick-to: 6.6
Fixes: QTBUG-114781
Change-Id: I4ee6f7d57c2836ef3dd9741d037d48181af2cdec
Reviewed-by: Marc Mutz <marc.mutz@qt.io>