f Use Vec::with_capacity where possible

Author: tnull

lightning-transaction-sync/src/electrum.rs

@@ -186,8 +186,9 @@ where
 		// First, check the confirmation status of registered transactions as well as the
 		// status of dependent transactions of registered outputs.
 		let mut confirmed_txs = Vec::new();
-		let mut watched_script_pubkeys = Vec::new();
-		let mut watched_txs = Vec::new();
+		let mut watched_script_pubkeys = Vec::with_capacity(
+			sync_state.watched_transactions.len() + sync_state.watched_outputs.len());
+		let mut watched_txs = Vec::with_capacity(sync_state.watched_transactions.len());
 		let watched_outputs = sync_state.watched_outputs.values().collect::<Vec<_>>();
 
 		for txid in &sync_state.watched_transactions {