Correcting the use of Box

Author: upjohnc

lightning-invoice/src/utils.rs

@@ -588,7 +588,7 @@ fn sort_and_filter_channels<L: Deref>(
     channels: Vec<ChannelDetails>,
     min_inbound_capacity_msat: Option<u64>,
     logger: &L,
-) -> Box<dyn Iterator<Item = RouteHint>>
+) -> impl Iterator<Item = RouteHint>
 where
     L::Target: Logger,
 {
@@ -617,7 +617,7 @@ where
 				// look at the public channels instead.
 				log_trace!(logger, "Not including channels in invoice route hints on account of public channel {}",
 					log_bytes!(channel.channel_id));
-				return Box::new(vec![].into_iter());
+                return vec![].into_iter().take(3).map(route_hint_from_channel);
 			}
 		}
 
@@ -689,7 +689,8 @@ where
 			cltv_expiry_delta: forwarding_info.cltv_expiry_delta,
 			htlc_minimum_msat: channel.inbound_htlc_minimum_msat,
 			htlc_maximum_msat: channel.inbound_htlc_maximum_msat,}])
-	};
+
+	}
 	// If all channels are private, prefer to return route hints which have a higher capacity than
 	// the payment value and where we're currently connected to the channel counterparty.
 	// Even if we cannot satisfy both goals, always ensure we include *some* hints, preferring
@@ -740,7 +741,7 @@ where
 				b.inbound_capacity_msat.cmp(&a.inbound_capacity_msat)
 			}});
 
-		Box::new(eligible_channels.into_iter().take(3).map(route_hint_from_channel))
+		eligible_channels.into_iter().take(3).map(route_hint_from_channel)
 }
 
 /// prefer_current_channel chooses a channel to use for route hints between a currently selected and candidate