Currently, Qt assumes that enums always have int as their underlying type (both in QMetaEnum::keyToValue and in the QML engine). This change makes it possible to to retrieve the underlying type from an enum's metaype - or rather, a metatype of an integral type with the same size and signedness. The use cases aobve don't really rely on the exact same type. In most cases, we wouldn't even need the signedness, however that is already available anyway, and it will come in handy once QML supports bigint, and we need to decide whether we should return While it would be possible for individual users of this function to manually query the size and signedness, having a function returning a metatype offers additional convenience - especially in QML, where the conversion APIs generally operate on metatypes. Task-number: QTBUG-27451 Task-number: QTBUG-84055 Task-number: QTBUG-112180 Change-Id: Icf733b42df0ea64017d69f4d94cb7c855d9e3201 Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>