Div. smart pointer/raii classes: mark ctors [[nodiscard]]

The following classes are smart pointers or RAII classes, whose ctors
QUIP-0019 asks to mark as [[nodiscard]]:

- QQmlMetaObjectPointer
- QQuickDeferredPointer
- QuitLockDisabler

QUIP: QUIP-0019
Fixes: QTBUG-104168
Pick-to: 6.6
Change-Id: Ia362f5d0eab7376f4536aefc61c31ceb296b1cc2
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

1 files changed, 3 insertions, 3 deletions

diff --git a/src/qml/qml/qqmlpropertycache_p.h b/src/qml/qml/qqmlpropertycache_p.h
index b261d1caca..a06a1b6e39 100644
--- a/src/qml/qml/qqmlpropertycache_p.h
+++ b/src/qml/qml/qqmlpropertycache_p.h
@@ -40,9 +40,9 @@ class QQmlVMEMetaObject;
 class QQmlMetaObjectPointer
 {
 public:
-    QQmlMetaObjectPointer() = default;
+    Q_NODISCARD_CTOR QQmlMetaObjectPointer() = default;
 
-    QQmlMetaObjectPointer(const QMetaObject *staticMetaObject)
+    Q_NODISCARD_CTOR QQmlMetaObjectPointer(const QMetaObject *staticMetaObject)
         : d(quintptr(staticMetaObject))
     {
         Q_ASSERT((d.loadRelaxed() & Shared) == 0);
@@ -57,7 +57,7 @@ public:
 
 private:
     friend class QQmlPropertyCache;
-    QQmlMetaObjectPointer(const QQmlMetaObjectPointer &other)
+    Q_NODISCARD_CTOR QQmlMetaObjectPointer(const QQmlMetaObjectPointer &other)
         : d(other.d.loadRelaxed())
     {
         // other has to survive until this ctor is done. So d cannot disappear before.