This allows to check whether QMetaTypeId2::MetaType exists, and can help
turn run-time into compile-time expressions, even without constexpr support,
or in situations where constexpr can't be used (because you can't overload
on it). This was designed for the QMetaType::registerConversion feature,
but it's much more widely applicable.
Change-Id: Iafa04add04bcb531b3f7fe3e751c7e91ee6a3bc0
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@nokia.com>