Function resource_equals

pub fn resource_equals<T>(value: T) -> impl FnMut(Res<'_, T>) -> bool
where
    T: Resource + PartialEq,

Generates a Condition-satisfying closure that returns true if the resource is equal to value.

Panics

The condition will panic if the resource does not exist.

Example

app.add_systems(
    // `resource_equals` will only return true if the given resource equals the given value
    my_system.run_if(resource_equals(Counter(0))),
);

fn my_system(mut counter: ResMut<Counter>) {
    counter.0 += 1;
}

// `Counter` is `0` so `my_system` can run
app.run(&mut world);
assert_eq!(world.resource::<Counter>().0, 1);

// `Counter` is no longer `0` so `my_system` won't run
app.run(&mut world);
assert_eq!(world.resource::<Counter>().0, 1);