path: root/src
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authorOlivier Goffart <>2015-02-22 10:02:08 +0100
committerOlivier Goffart (Woboq GmbH) <>2015-03-18 07:33:19 +0000
commit7c77013c7f6ec57cd1b1faf3b480c40a619067c8 (patch)
treefed2bafa9d5bbc6545557de2490d8f00bf127c78 /src
parent59c402417122e2ec2ee3c49b5768646581103d47 (diff)
Fix source incompatibility while connecting signals with forward declared arguments
QObject::connect tries to determine if the arguments are registered metatypes. This used to work even for arguments that were forward declared. But now, the metatype system tries to call QtPrivate::IsQEnumHelper<T>::Value to know if it is registered. That fails on gcc if T is forward declared. Apparently gcc needs to know the full type of T to pass it in the ellipsis function, even within a sizeof expression. So change the ellipsis expression to a template one. Task-number: QTBUG-44496 Change-Id: I7fa07bd3cde470b134c2ec53b0d581333d16a6f1 Reviewed-by: Thiago Macieira <>
Diffstat (limited to 'src')
1 files changed, 4 insertions, 4 deletions
diff --git a/src/corelib/kernel/qmetatype.h b/src/corelib/kernel/qmetatype.h
index 2c2dbeef9d..55f8fc9b2c 100644
--- a/src/corelib/kernel/qmetatype.h
+++ b/src/corelib/kernel/qmetatype.h
@@ -1364,15 +1364,15 @@ namespace QtPrivate
enum { Value = sizeof(checkType(static_cast<T*>(0))) == sizeof(void*) };
- char qt_getEnumMetaObject(...);
- char qt_getEnumMetaObject(); // Workaround bugs in MSVC.
+ template<typename T> char qt_getEnumMetaObject(const T&);
template<typename T>
struct IsQEnumHelper {
static const T &declval();
- // If the type was declared with Q_ENUM, the friend qt_getEnumMetaObject(T) declared in the
+ // If the type was declared with Q_ENUM, the friend qt_getEnumMetaObject() declared in the
// Q_ENUM macro will be chosen by ADL, and the return type will be QMetaObject*.
- // Otherwise the chosen overload will be qt_getEnumMetaObject(...) which returne 'char'
+ // Otherwise the chosen overload will be the catch all template function
+ // qt_getEnumMetaObject(T) which returns 'char'
enum { Value = sizeof(qt_getEnumMetaObject(declval())) == sizeof(QMetaObject*) };