Fix some minor code lint issues

Author: oschwald

examples/within.rs

@@ -13,15 +13,15 @@ fn main() -> Result<(), String> {
         .ok_or("Second argument must be the IP address and mask in CIDR notation, e.g. 0.0.0.0/0 or ::/0")?
         .parse()
         .unwrap();
-    let ip_net = if cidr.contains(":") {
+    let ip_net = if cidr.contains(':') {
         IpNetwork::V6(cidr.parse().unwrap())
     } else {
         IpNetwork::V4(cidr.parse().unwrap())
     };
 
     let mut n = 0;
     let mut iter: Within<geoip2::City, _> = reader.within(ip_net).map_err(|e| e.to_string())?;
-    while let Some(next) = iter.next() {
+    for next in iter {
         let item = next.map_err(|e| e.to_string())?;
         let continent = item.info.continent.and_then(|c| c.code).unwrap_or("");
         let country = item.info.country.and_then(|c| c.iso_code).unwrap_or("");

src/maxminddb/lib.rs

@@ -304,7 +304,7 @@ impl<'de, S: AsRef<[u8]>> Reader<S> {
         // Traverse down the tree to the level that matches the cidr mark
         let mut i = 0_usize;
         while i < prefix_len {
-            let bit = 1 & (ip_bytes[i >> 3] >> 7 - (i % 8)) as usize;
+            let bit = 1 & (ip_bytes[i >> 3] >> (7 - (i % 8))) as usize;
             node = self.read_node(node, bit)?;
             if node >= node_count {
                 // We've hit a dead end before we exhausted our prefix

src/maxminddb/reader_test.rs

@@ -357,7 +357,7 @@ fn test_within_city() {
     assert_eq!(item.info.city.unwrap().geoname_id, Some(2655045));
 
     let mut n = 1;
-    while let Some(_) = iter.next() {
+    for _ in iter {
         n += 1;
     }
 
@@ -375,7 +375,7 @@ fn test_within_city() {
         IpNetwork::V4("81.2.69.144/28".parse().unwrap()),
         IpNetwork::V4("81.2.69.142/31".parse().unwrap()),
     ];
-    while expected.len() > 0 {
+    while !expected.is_empty() {
         let e = expected.pop().unwrap();
         let item = iter.next().unwrap().unwrap();
         assert_eq!(item.ip_net, e);