Yeah, basically. QThreadPool just uses a simple int for priorities, starting at 0. Not sure if it was a design decision by the Qt people to not use an enum, or what.

IIRC, LowEventPriority corresponds to -1, which causes the thread to never start because it's less than 0 (that might be a Qt bug). So the Qt::EventPriority enum just wasn't meant to be used with QThreadPool, it seems.