diff --git a/2021/src/day15.rs b/2021/src/day15.rs
index c46e09e..f60a472 100644
--- a/2021/src/day15.rs
+++ b/2021/src/day15.rs
@@ -114,7 +114,7 @@ impl Debug for Edge {
 // to each node. This implementation isn't memory-efficient as it may leave duplicate
 // nodes in the queue. It also uses `usize::MAX` as a sentinel value,
 // for a simpler implementation.
-fn shortest_path(adj_list: &Vec<Vec<Edge>>, start: usize, goal: usize) -> Option<usize> {
+fn shortest_path(adj_list: &[Vec<Edge>], start: usize, goal: usize) -> Option<usize> {
     // dist[node] = current shortest distance from `start` to `node`
     let mut dist: Vec<_> = (0..adj_list.len()).map(|_| usize::MAX).collect();
 
diff --git a/2021/src/day16.rs b/2021/src/day16.rs
index 92f164e..c9ec419 100644
--- a/2021/src/day16.rs
+++ b/2021/src/day16.rs
@@ -11,18 +11,18 @@ fn hex(b: &u8) -> u8 {
 
 fn sum_version(packet: &Packet) -> u64 {
     fn sum_packets(packets: &[Packet]) -> u64 {
-        packets.iter().map(|p| sum_version(p)).sum()
+        packets.iter().map(sum_version).sum()
     }
     packet.version as u64
         + match &packet.packet_type {
-            PacketType::Sum(packets) => sum_packets(&packets),
-            PacketType::Product(packets) => sum_packets(&packets),
-            PacketType::Minimum(packets) => sum_packets(&packets),
-            PacketType::Maximum(packets) => sum_packets(&packets),
+            PacketType::Sum(packets) => sum_packets(packets),
+            PacketType::Product(packets) => sum_packets(packets),
+            PacketType::Minimum(packets) => sum_packets(packets),
+            PacketType::Maximum(packets) => sum_packets(packets),
             PacketType::Literal(_) => 0,
-            PacketType::GreaterThan(packets) => sum_packets(&packets),
-            PacketType::LessThan(packets) => sum_packets(&packets),
-            PacketType::Equal(packets) => sum_packets(&packets),
+            PacketType::GreaterThan(packets) => sum_packets(packets),
+            PacketType::LessThan(packets) => sum_packets(packets),
+            PacketType::Equal(packets) => sum_packets(packets),
         }
 }
 
@@ -114,7 +114,7 @@ impl<'a> Parser<'a> {
         let v = (self.tmp >> self.tmp_len) & mask;
 
         let mask = (1 << self.tmp_len) - 1;
-        self.tmp = self.tmp & mask;
+        self.tmp &= mask;
 
         //println!( "   END n {0} tmp 0b{2:b} len {3} v 0b{1:00$b} ", n, v, self.tmp, self.tmp_len);
         v as u64
diff --git a/2021/src/day17.rs b/2021/src/day17.rs
index a7db66e..0536851 100644
--- a/2021/src/day17.rs
+++ b/2021/src/day17.rs
@@ -1,5 +1,5 @@
 use advent::prelude::*;
-use aoc_runner_derive::{aoc, aoc_generator};
+use aoc_runner_derive::aoc;
 
 #[derive(Debug)]
 struct Target {
@@ -43,11 +43,11 @@ impl FromStr for Target {
         let y = &parts[3][2..];
         let (x_min, x_max) = x
             .split_once("..")
-            .and_then(|(min, max)| Some((min.parse().unwrap(), max.parse().unwrap())))
+            .map(|(min, max)| (min.parse().unwrap(), max.parse().unwrap()))
             .unwrap();
         let (y_min, y_max) = y
             .split_once("..")
-            .and_then(|(min, max)| Some((min.parse().unwrap(), max.parse().unwrap())))
+            .map(|(min, max)| (min.parse().unwrap(), max.parse().unwrap()))
             .unwrap();
 
         Ok(Target {
diff --git a/2021/src/day4.rs b/2021/src/day4.rs
index 795d5f1..ec6eb59 100644
--- a/2021/src/day4.rs
+++ b/2021/src/day4.rs
@@ -161,8 +161,7 @@ impl MarkerBoard {
         let m = self.0;
 
         // Bingo horizontally
-        false
-            || (m & h == h)
+        (m & h == h)
             || ((m >> 5 & h) == h)
             || ((m >> 10 & h) == h)
             || ((m >> 15 & h) == h)