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use crate::consumer;
use crate::feed::Feed;
use crate::consumer::Consumer;
use crate::feed::Result;
#[derive(Clone, Debug, PartialEq, Default)]
pub struct Maybe<T : Feed> (Option<T>);
impl<T : Feed + Clone> Maybe<T> {
fn inner(&self) -> Option<T> {
self.0.clone()
}
}
impl<T : Feed + Default + Clone> Feed for Maybe<T> {
fn feed(&mut self, consumer: &mut Consumer) -> Result {
let ref mut consumer_cloned = consumer.clone();
let ref mut feed = T::default();
let result = consumer_cloned.consume(feed);
if result.is_ok() {
consumer.clone_from(consumer_cloned);
self.0 = Some(feed.clone());
Ok(())
}
else { Ok(()) }
}
}