QMetaCallEvent::create: extract template-argument-independent code

Extract Method create_impl() with all the stuff that doesn't depend on
create()'s template arguments, which will reduce compile time and
amount of generated code.

Change-Id: I9d8f59c168873ac3527b570ef6142079824061cf
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit dc7820a296d58cc61628addd010e28d893d4950b)
Reviewed-by: Marc Mutz <marc.mutz@qt.io>

src/corelib/kernel/qobject.cpp

@@ -624,6 +624,25 @@ void QMetaCallEvent::placeMetaCall(QObject *object)
     }
 }
 
+QMetaCallEvent* QMetaCallEvent::create_impl(QtPrivate::QSlotObjectBase *slotObj,
+                                            const QObject *sender, int signal_index,
+                                            size_t argc, const void* const argp[],
+                                            const QMetaType metaTypes[])
+{
+    auto metaCallEvent = std::make_unique<QMetaCallEvent>(slotObj, sender,
+                                                          signal_index, int(argc));
+
+    void **args = metaCallEvent->args();
+    QMetaType *types = metaCallEvent->types();
+    for (size_t i = 0; i < argc; ++i) {
+        types[i] = metaTypes[i];
+        args[i] = types[i].create(argp[i]);
+        Q_CHECK_PTR(!i || args[i]);
+    }
+
+    return metaCallEvent.release();
+}
+
 /*!
     \class QSignalBlocker
     \brief Exception-safe wrapper around QObject::blockSignals().

src/corelib/kernel/qobject_p.h

@@ -394,18 +394,7 @@ public:
         const void* const argp[] = { nullptr, std::addressof(argv)... };
         const QMetaType metaTypes[] = { QMetaType::fromType<void>(), QMetaType::fromType<Args>()... };
         constexpr auto argc = sizeof...(Args) + 1;
-        auto metaCallEvent = std::make_unique<QMetaCallEvent>(slotObj, sender,
+        return create_impl(slotObj, sender, signal_index, argc, argp, metaTypes);
-                                                              signal_index, int(argc));
-
-        void **args = metaCallEvent->args();
-        QMetaType *types = metaCallEvent->types();
-        for (size_t i = 0; i < argc; ++i) {
-            types[i] = metaTypes[i];
-            args[i] = types[i].create(argp[i]);
-            Q_CHECK_PTR(!i || args[i]);
-        }
-
-        return metaCallEvent.release();
     }
 
     inline int id() const { return d.method_offset_ + d.method_relative_; }
@@ -417,6 +406,9 @@ public:
     virtual void placeMetaCall(QObject *object) override;
 
 private:
+    static QMetaCallEvent *create_impl(QtPrivate::QSlotObjectBase *slotObj, const QObject *sender,
+                                       int signal_index, size_t argc, const void * const argp[],
+                                       const QMetaType metaTypes[]);
     inline void allocArgs();
 
     struct Data {