Struct ConditionalFn 

pub struct ConditionalFn<S, F> { /* private fields */ }

Wraps a System, skipping it for a tick whenever cond returns false. The closure-based counterpart to Conditional — see RunIfFnExt::run_if_fn.

Trait Implementations

impl<S: System, F: Fn(&World, &Resources) -> bool + 'static> System for ConditionalFn<S, F>

fn run(&mut self, world: &World, resources: &Resources)

fn name(&self) -> &'static str

Human-readable identifier for this system, used in error/trace output so a missing-resource failure can be pinned to the system that needs it instead of just the resource name. Defaults to the type name of the System impl; FunctionSystem overrides this with the name of the wrapped function/closure, which is far more legible.

fn requires(&self) -> Vec<RequiredResource>

Resource types this system needs present, derived automatically from its bare Res/ResMut parameters. App checks these before running a non-convergent stage’s systems and panics with a clear message naming the missing resource(s) rather than letting a param fetch panic deep inside whichever system happens to run first.