+- QMetaType
+
+ * Interpretation of QMetaType::Void was changed. Before, in some cases
+ it was returned as an invalid type id, but sometimes it was used as a valid
+ type (C++ "void"). In Qt5, new QMetaType::UnknownType was introduced to
+ distinguish between these two. QMetaType::UnknownType is an invalid type id
+ signaling that a type is unknown to QMetaType, and QMetaType::Void
+ is a valid type id of C++ void type. The difference will be visible for
+ example in call to QMetaType::typeName(), this function will return null for
+ QMetaType::UnknownType and a pointer to "void" string for
+ QMetaType::Void.
+ Please, notice that QMetaType::UnknownType has value 0, which previously was
+ reserved for QMetaType::Void.
+