diff options
author | Volker Hilsheimer <volker.hilsheimer@qt.io> | 2023-06-22 09:53:23 +0200 |
---|---|---|
committer | Marc Mutz <marc.mutz@qt.io> | 2023-06-22 13:20:26 +0000 |
commit | 2b9ef2eb44c084d39ef8324cfe1ae42a98b3038f (patch) | |
tree | d212460280257673fdfc0570398332733961dd81 /src/corelib/kernel/qobject.h | |
parent | c33fd574c970eb920a899a9caccb2e6b1838ee19 (diff) |
Pacify MSVC compiler incorrectly warning about unused variable
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>
Diffstat (limited to 'src/corelib/kernel/qobject.h')
-rw-r--r-- | src/corelib/kernel/qobject.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/src/corelib/kernel/qobject.h b/src/corelib/kernel/qobject.h index 49435b9701..182edaf7f2 100644 --- a/src/corelib/kernel/qobject.h +++ b/src/corelib/kernel/qobject.h @@ -207,6 +207,7 @@ public: "Return type of the slot is not compatible with the return type of the signal."); } else { constexpr int FunctorArgumentCount = QtPrivate::ComputeFunctorArgumentCount<std::decay_t<Func2>, typename SignalType::Arguments>::Value; + [[maybe_unused]] constexpr int SlotArgumentCount = (FunctorArgumentCount >= 0) ? FunctorArgumentCount : 0; typedef typename QtPrivate::FunctorReturnType<std::decay_t<Func2>, typename QtPrivate::List_Left<typename SignalType::Arguments, SlotArgumentCount>::Value>::Value SlotReturnType; |