usecrate::entity::Entity;usecrate::NoSuchEntity;/// Type that can be registered. Can be used to set components in ECS Worlds generated by `genesis`.
pubtraitRegister<T> {/// Register the given item for the given entity.
/// Returns Err(NoSuchEntity) if the given entity doesn't exist.
/// Otherwise, returns the previously associated item.
/// For normal components used to generate a World, this is equivalent to calling `.set()`
/// on the corresponding storage field.
fnregister(&mutself, entity: Entity, item: T)->Result<Option<T>, NoSuchEntity>;}