Mmh well actually i won't need the set in this particular game, i just liked the idea

For this one i'll rely on events to handle user inputs. Main loop will be used only for drawing purpose. Actually, Qt is class based, so events are outside the main loop.
In SDL context, events were put in an event queue and polled at every refresh, so a set would be wonderful there.

But here i'm using a timer for refresh, events aren't syncronized with this timer because i'm keeping objects interact asyncronously: a physic engine will have its loop for integrate the simulation, GLwidget loop will have its loop for refreshing the screen, but the game under the hood isn't synced.

Well, i'm just trying this approach, since it's the first time i do a game with Qt (and C++)... If i'll found that doesn't work good, i'll use the classic method

Thanks anyway