Don't show no_effect warning on unit structs implementing fn_once Fixes #7792 changelog: Don't show [`no_effect`] or [`unecessary_operation`] warning for unit struct implementing FnOnce
Don't show no_effect warning on unit structs implementing fn_once Fixes #7792 changelog: Don't show [`no_effect`] or [`unecessary_operation`] warning for unit struct implementing FnOnce