QMetaType: create metatype for void

Create a QMetaTypeInterface for void. This allows us differentiate
QMetaType::Unknown from QMetaType::Void. In addition, this will enable
the usage of QMetaMethod::metaReturnType in QMetaMethod::returnType,
and will facilitate using metaReturnType in declarative, which needs to
distinguish between Unknown and Void.

Change-Id: I83296b49587f3deb7ec73e25a33f0d8c98cf8da0
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 11 insertions, 2 deletions

diff --git a/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp b/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp
index f144aad7e4..d036be55c6 100644
--- a/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp
+++ b/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp
@@ -127,6 +127,7 @@ private slots:
     void operatorEq_data();
     void operatorEq();
     void typesWithInaccessibleDTors();
+    void voidIsNotUnknown();
 };
 
 struct BaseGenericType
@@ -1339,7 +1340,7 @@ void tst_QMetaType::isRegistered_data()
     QTest::addColumn<bool>("registered");
 
     // predefined/custom types
-    QTest::newRow("QMetaType::Void") << int(QMetaType::Void) << false;
+    QTest::newRow("QMetaType::Void") << int(QMetaType::Void) << true;
     QTest::newRow("QMetaType::Int") << int(QMetaType::Int) << true;
 
     int dummyTypeId = qRegisterMetaType<IsRegisteredDummyType>("IsRegisteredDummyType");
@@ -2548,7 +2549,7 @@ void tst_QMetaType::operatorEq_data()
     QTest::newRow("String") << QMetaType(QMetaType::QString)
                             << QMetaType::fromType<const QString &>() << true;
     QTest::newRow("void1") << QMetaType(QMetaType::UnknownType) << QMetaType::fromType<void>()
-                           << true;
+                           << false;
     QTest::newRow("void2") << QMetaType::fromType<const void>() << QMetaType::fromType<void>()
                            << true;
     QTest::newRow("vec1") << QMetaType::fromType<QVector<const int *>>()
@@ -2590,6 +2591,14 @@ void tst_QMetaType::typesWithInaccessibleDTors()
     Q_UNUSED(QMetaType::fromType<WithDeletedDtor>());
 }
 
+void tst_QMetaType::voidIsNotUnknown()
+{
+    QMetaType voidType = QMetaType::fromType<void>();
+    QMetaType voidType2 = QMetaType(QMetaType::Void);
+    QCOMPARE(voidType, voidType2);
+    QVERIFY(voidType != QMetaType(QMetaType::UnknownType));
+}
+
 // Compile-time test, it should be possible to register function pointer types
 class Undefined;