1 files changed, 93 insertions, 1 deletions

diff --git a/src/corelib/kernel/qobjectdefs_impl.h b/src/corelib/kernel/qobjectdefs_impl.h
index c91259d559..da356095af 100644
--- a/src/corelib/kernel/qobjectdefs_impl.h
+++ b/src/corelib/kernel/qobjectdefs_impl.h
@@ -51,7 +51,7 @@
 #endif
 
 QT_BEGIN_NAMESPACE
-
+class QObject;
 
 namespace QtPrivate {
     template <typename T> struct RemoveRef { typedef T Type; };
@@ -352,6 +352,98 @@ namespace QtPrivate {
         template <typename D> static D dummy();
         typedef decltype(dummy<Functor>().operator()((dummy<ArgList>())...)) Value;
     };
+
+    // internal base class (interface) containing functions required to call a slot managed by a pointer to function.
+    class QSlotObjectBase {
+        QAtomicInt m_ref;
+        // don't use virtual functions here; we don't want the
+        // compiler to create tons of per-polymorphic-class stuff that
+        // we'll never need. We just use one function pointer.
+        typedef void (*ImplFn)(int which, QSlotObjectBase* this_, QObject *receiver, void **args, bool *ret);
+        const ImplFn m_impl;
+    protected:
+        enum Operation {
+            Destroy,
+            Call,
+            Compare,
+
+            NumOperations
+        };
+    public:
+        explicit QSlotObjectBase(ImplFn fn) : m_ref(1), m_impl(fn) {}
+
+        inline int ref() Q_DECL_NOTHROW { return m_ref.ref(); }
+        inline void destroyIfLastRef() Q_DECL_NOTHROW
+        { if (!m_ref.deref()) m_impl(Destroy, this, Q_NULLPTR, Q_NULLPTR, Q_NULLPTR); }
+
+        inline bool compare(void **a) { bool ret = false; m_impl(Compare, this, Q_NULLPTR, a, &ret); return ret; }
+        inline void call(QObject *r, void **a)  { m_impl(Call,    this, r, a, Q_NULLPTR); }
+    protected:
+        ~QSlotObjectBase() {}
+    private:
+        Q_DISABLE_COPY(QSlotObjectBase)
+    };
+
+    // implementation of QSlotObjectBase for which the slot is a pointer to member function of a QObject
+    // Args and R are the List of arguments and the returntype of the signal to which the slot is connected.
+    template<typename Func, typename Args, typename R> class QSlotObject : public QSlotObjectBase
+    {
+        typedef QtPrivate::FunctionPointer<Func> FuncType;
+        Func function;
+        static void impl(int which, QSlotObjectBase *this_, QObject *r, void **a, bool *ret)
+        {
+            switch (which) {
+            case Destroy:
+                delete static_cast<QSlotObject*>(this_);
+                break;
+            case Call:
+                FuncType::template call<Args, R>(static_cast<QSlotObject*>(this_)->function, static_cast<typename FuncType::Object *>(r), a);
+                break;
+            case Compare:
+                *ret = *reinterpret_cast<Func *>(a) == static_cast<QSlotObject*>(this_)->function;
+                break;
+            case NumOperations: ;
+            }
+        }
+    public:
+        explicit QSlotObject(Func f) : QSlotObjectBase(&impl), function(f) {}
+    };
+    // implementation of QSlotObjectBase for which the slot is a functor (or lambda)
+    // N is the number of arguments
+    // Args and R are the List of arguments and the returntype of the signal to which the slot is connected.
+    template<typename Func, int N, typename Args, typename R> class QFunctorSlotObject : public QSlotObjectBase
+    {
+        typedef QtPrivate::Functor<Func, N> FuncType;
+        Func function;
+        static void impl(int which, QSlotObjectBase *this_, QObject *r, void **a, bool *ret)
+        {
+            switch (which) {
+            case Destroy:
+                delete static_cast<QFunctorSlotObject*>(this_);
+                break;
+            case Call:
+                FuncType::template call<Args, R>(static_cast<QFunctorSlotObject*>(this_)->function, r, a);
+                break;
+            case Compare: // not implemented
+            case NumOperations:
+                Q_UNUSED(ret);
+            }
+        }
+    public:
+        explicit QFunctorSlotObject(Func f) : QSlotObjectBase(&impl), function(std::move(f)) {}
+    };
+
+    // typedefs for readability for when there are no parameters
+    template <typename Func>
+    using QSlotObjectWithNoArgs = QSlotObject<Func,
+                                              QtPrivate::List<>,
+                                              typename QtPrivate::FunctionPointer<Func>::ReturnType>;
+
+    template <typename Func, typename R>
+    using QFunctorSlotObjectWithNoArgs = QFunctorSlotObject<Func, 0, QtPrivate::List<>, R>;
+
+    template <typename Func>
+    using QFunctorSlotObjectWithNoArgsImplicitReturn = QFunctorSlotObjectWithNoArgs<Func, typename QtPrivate::FunctionPointer<Func>::ReturnType>;
 }
 
 QT_END_NAMESPACE