Decide if EventReader::clear() should return a bool

[IceSentry]

We need to determine which option is best for #4693

Option 1.

Clear doesn't return anything and you need to use .is_empty()

fn system(events: EventReader<MyEvent>) {
	if !events.is_empty {
		events.clear();
		// Process the fact that one or more event was received
	}
}

Option 2.

It returns whether or not there was any events to clear.

fn system(events: EventReader<MyEvent>) {
	if events.clear() {
		// Process the fact that one or more event was received
	}
}

[mockersf]

clear() is often used in std https://doc.rust-lang.org/stable/std/?search=clear and doesn't return anything

[Evrey]

I’d not be against just adding a third method in the spirit of staying with libstd convention. Such as: checked_clear, clear_and_is_empty, maybe_clear,…

[tigregalis]

In the same vein, I suggest clear_then.

fn system(events: EventReader<MyEvent>) {
	if events.clear_then() {
		// Process the fact that one or more event was received
	}
}

[Evrey]

By libstd conventions, _then would take a lambda.

[IceSentry]

Just letting you know, the PR is already merged. We decided to make clear() not return anything. You can open a new PR if you want, but this discussion is essentially closed, I'm just not sure how to close a discussion

[Evrey]

Ah, fun. =D