diff options
Diffstat (limited to 'src/corelib/kernel/qobject.h')
| -rw-r--r-- | src/corelib/kernel/qobject.h | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/src/corelib/kernel/qobject.h b/src/corelib/kernel/qobject.h index 7beaa32855..aaa09fac50 100644 --- a/src/corelib/kernel/qobject.h +++ b/src/corelib/kernel/qobject.h @@ -1,6 +1,7 @@ /**************************************************************************** ** ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). +** Copyright (C) 2013 Olivier Goffart <ogoffart@woboq.com> ** Contact: http://www.qt-project.org/legal ** ** This file is part of the QtCore module of the Qt Toolkit. @@ -265,27 +266,50 @@ public: static inline typename QtPrivate::QEnableIf<QtPrivate::FunctionPointer<Func2>::ArgumentCount == -1, QMetaObject::Connection>::Type connect(const typename QtPrivate::FunctionPointer<Func1>::Object *sender, Func1 signal, Func2 slot) { +#if defined (Q_COMPILER_DECLTYPE) && defined (Q_COMPILER_VARIADIC_TEMPLATES) + typedef QtPrivate::FunctionPointer<Func1> SignalType; + const int FunctorArgumentCount = QtPrivate::ComputeFunctorArgumentCount<Func2 , typename SignalType::Arguments>::Value; + + Q_STATIC_ASSERT_X((FunctorArgumentCount >= 0), + "Signal and slot arguments are not compatible."); + const int SlotArgumentCount = (FunctorArgumentCount >= 0) ? FunctorArgumentCount : 0; + typedef typename QtPrivate::FunctorReturnType<Func2, typename QtPrivate::List_Left<typename SignalType::Arguments, SlotArgumentCount>::Value>::Value SlotReturnType; +#else + // Without variadic template, we don't detect the best overload of operator(). We just + // assume there is only one simple operator() and connect to &Func2::operator() + + /* If you get an error such as: + couldn't deduce template parameter 'Func2Operator' + or + cannot resolve address of overloaded function + It means the functor does not have a single operator(). + Functors with overloaded or templated operator() are only supported if the compiler supports + C++11 variadic templates + */ #ifndef Q_COMPILER_DECLTYPE //Workaround the lack of decltype using another function as indirection return connect_functor(sender, signal, slot, &Func2::operator()); } template <typename Func1, typename Func2, typename Func2Operator> static inline QMetaObject::Connection connect_functor(const QObject *sender, Func1 signal, Func2 slot, Func2Operator) { typedef QtPrivate::FunctionPointer<Func2Operator> SlotType ; #else - typedef QtPrivate::FunctionPointer<decltype(&Func2::operator())> SlotType ; #endif typedef QtPrivate::FunctionPointer<Func1> SignalType; + typedef typename SlotType::ReturnType SlotReturnType; + const int SlotArgumentCount = SlotType::ArgumentCount; - Q_STATIC_ASSERT_X(int(SignalType::ArgumentCount) >= int(SlotType::ArgumentCount), + Q_STATIC_ASSERT_X(int(SignalType::ArgumentCount) >= SlotArgumentCount, "The slot requires more arguments than the signal provides."); Q_STATIC_ASSERT_X((QtPrivate::CheckCompatibleArguments<typename SignalType::Arguments, typename SlotType::Arguments>::value), "Signal and slot arguments are not compatible."); - Q_STATIC_ASSERT_X((QtPrivate::AreArgumentsCompatible<typename SlotType::ReturnType, typename SignalType::ReturnType>::value), +#endif + + Q_STATIC_ASSERT_X((QtPrivate::AreArgumentsCompatible<SlotReturnType, typename SignalType::ReturnType>::value), "Return type of the slot is not compatible with the return type of the signal."); return connectImpl(sender, reinterpret_cast<void **>(&signal), sender, 0, - new QtPrivate::QFunctorSlotObject<Func2, SlotType::ArgumentCount, - typename QtPrivate::List_Left<typename SignalType::Arguments, SlotType::ArgumentCount>::Value, + new QtPrivate::QFunctorSlotObject<Func2, SlotArgumentCount, + typename QtPrivate::List_Left<typename SignalType::Arguments, SlotArgumentCount>::Value, typename SignalType::ReturnType>(slot), Qt::DirectConnection, 0, &SignalType::Object::staticMetaObject); } |