Support move-only functors in invokeMethod and async APIs

Move-only functors must never be passed by value, so fix the
QFunctorSlotObject constructor accordingly.

This then requires adjustments to the various QMetaMethod::invokeMethod
overloads, as those must also perfectly forwad the functor type.

Enable the previously failing test case for move-only functors.

Change-Id: I9c544fd3ddbc5e1da3ca193236291a9f83d86211
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 4 insertions, 7 deletions

diff --git a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
index 9c18a2a0f6..649f075a02 100644
--- a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
+++ b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
@@ -8434,6 +8434,7 @@ void tst_QObject::asyncCallbackHelper()
     static_assert(compiles<AsyncCaller::Prototype0>(&AsyncCaller::callback0));
     static_assert(compiles<AsyncCaller::Prototype0>(&AsyncCaller::staticCallback0));
     static_assert(compiles<AsyncCaller::Prototype0>(lambda0));
+    static_assert(compiles<AsyncCaller::Prototype0>(moveOnlyLambda));
     static_assert(compiles<AsyncCaller::Prototype0>(freeFunction0));
     static_assert(compiles<AsyncCaller::Prototype0>(functor0));
 
@@ -8448,6 +8449,7 @@ void tst_QObject::asyncCallbackHelper()
     static_assert(compiles<AsyncCaller::Prototype1>(&AsyncCaller::callback1));
     static_assert(compiles<AsyncCaller::Prototype1>(&AsyncCaller::staticCallback1));
     static_assert(compiles<AsyncCaller::Prototype1>(lambda1));
+    static_assert(compiles<AsyncCaller::Prototype1>(moveOnlyLambda));
     static_assert(compiles<AsyncCaller::Prototype1>(constLambda));
     static_assert(compiles<AsyncCaller::Prototype1>(freeFunction1));
     static_assert(compiles<AsyncCaller::Prototype1>(functor1));
@@ -8461,11 +8463,6 @@ void tst_QObject::asyncCallbackHelper()
     static_assert(!compiles<AsyncCaller::Prototype0>(freeFunction1));
     static_assert(!compiles<AsyncCaller::Prototype0>(functor1));
 
-    // move-only functor - should work, but doesn't because QFunctorSlotObject requires
-    // the functor to be of a copyable type!
-    static_assert(!compiles<AsyncCaller::Prototype0>(moveOnlyLambda));
-    static_assert(!compiles<AsyncCaller::Prototype1>(moveOnlyLambda));
-
     // wrong parameter type
     static_assert(!compiles<AsyncCaller::Prototype1>(&AsyncCaller::callbackInt));
 
@@ -8483,7 +8480,7 @@ void tst_QObject::asyncCallbackHelper()
     QVERIFY(caller.callMe0(&caller, &AsyncCaller::staticCallback0));
     QVERIFY(caller.callMe0(&caller, lambda0));
     QVERIFY(caller.callMe0(&caller, freeFunction0));
-//    QVERIFY(caller.callMe0(&caller, moveOnlyLambda));
+    QVERIFY(caller.callMe0(&caller, moveOnlyLambda));
 
     QVERIFY(caller.callMe1(&caller, &AsyncCaller::callback1));
     QVERIFY(caller.callMe1(&caller, &AsyncCaller::staticCallback1));
@@ -8495,7 +8492,7 @@ void tst_QObject::asyncCallbackHelper()
     QVERIFY(caller.callMe0(&AsyncCaller::staticCallback0));
     QVERIFY(caller.callMe0(lambda0));
     QVERIFY(caller.callMe0(freeFunction0));
-//    QVERIFY(caller.callMe0(moveOnlyLambda));
+    QVERIFY(caller.callMe0(moveOnlyLambda));
 
     QVERIFY(caller.callMe1(&AsyncCaller::staticCallback1));
     QVERIFY(caller.callMe1(lambda1));