QObject: fix connection to function pointer with non-copyable references argument

For example, QObject is non copyable (its copy constructor is deleted or
private via Q_DISABLE_COPY). It should still be allowed to pass a reference
to a QObject as an argument to as signal (or slot).
This fixes a compilation failure.

Task-number: QTBUG-36119
Change-Id: I9bcf477e347d69fdae2543c99781b6421883be78
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/corelib/kernel/qobjectdefs_impl.h b/src/corelib/kernel/qobjectdefs_impl.h
index fb6601f21b..de6f65ab7d 100644
--- a/src/corelib/kernel/qobjectdefs_impl.h
+++ b/src/corelib/kernel/qobjectdefs_impl.h
@@ -567,9 +567,9 @@ namespace QtPrivate {
        Q_STATIC_ASSERT(CheckCompatibleArguments<FunctionPointer<Signal>::Arguments, FunctionPointer<Slot>::Arguments>::value)
     */
     template<typename A1, typename A2> struct AreArgumentsCompatible {
-        static int test(A2);
+        static int test(const typename RemoveRef<A2>::Type&);
         static char test(...);
-        static A1 dummy();
+        static const typename RemoveRef<A1>::Type &dummy();
         enum { value = sizeof(test(dummy())) == sizeof(int) };
     };
     template<typename A1, typename A2> struct AreArgumentsCompatible<A1, A2&> { enum { value = false }; };