Apply clippy fixes.

Author: brndnmtthws

src/bin/c01p02.rs

@@ -13,15 +13,15 @@ fn is_permutation(s1: &str, s2: &str) -> bool {
     let characters_2 = count_chars(s2);
 
     for key in characters_1.keys() {
-        if !characters_2.contains_key(&key) {
+        if !characters_2.contains_key(key) {
             return false;
         }
-        if characters_1.get(&key) != characters_2.get(&key) {
+        if characters_1.get(key) != characters_2.get(key) {
             return false;
         }
     }
     for key in characters_2.keys() {
-        if !characters_1.contains_key(&key) {
+        if !characters_1.contains_key(key) {
             return false;
         }
     }

src/bin/c01p03.rs

@@ -12,7 +12,7 @@ fn urlify(url: &'static str) -> String {
 
 // Alternative solution with shorter syntax
 fn urlify_2(url: &str) -> String {
-    url.trim().replace(" ", "%20")
+    url.trim().replace(' ', "%20")
 }
 
 #[cfg(test)]
@@ -21,15 +21,15 @@ mod tests {
 
     #[test]
     fn test_urlify() {
-        assert_eq!(urlify(&"Mr John Smith    "), "Mr%20John%20Smith");
+        assert_eq!(urlify("Mr John Smith    "), "Mr%20John%20Smith");
     }
     #[test]
     fn test_urlify_2() {
-        assert_eq!(urlify_2(&"Mr John Smith    "), "Mr%20John%20Smith");
+        assert_eq!(urlify_2("Mr John Smith    "), "Mr%20John%20Smith");
     }
 }
 
 fn main() {
-    urlify(&"Mr John Smith    ");
-    urlify_2(&"Mr John Smith    ");
+    urlify("Mr John Smith    ");
+    urlify_2("Mr John Smith    ");
 }

src/bin/c05p07.rs

@@ -1,7 +1,5 @@
 fn bitwise_swap(a: &mut i32, b: &mut i32) {
-    *a ^= *b;
-    *b ^= *a;
-    *a ^= *b;
+    std::mem::swap(&mut (*a), &mut (*b))
 }
 
 #[cfg(test)]

src/bin/c07p03.rs

@@ -46,11 +46,7 @@ impl Jukebox {
         if self.queue.is_empty() {
             // pick random song
             let mut rng = thread_rng();
-            if let Some(song) = self.catalogue.choose(&mut rng) {
-                Some(song.clone())
-            } else {
-                None
-            }
+            self.catalogue.choose(&mut rng).cloned()
         } else {
             Some(self.queue.remove(0))
         }

src/bin/c08p02.rs

@@ -1,4 +1,4 @@
-#![allow(clippy::same_item_push, clippy::unknown_clippy_lints)]
+#![allow(clippy::same_item_push, unknown_lints)]
 
 #[derive(Clone, Copy, Debug, PartialEq)]
 struct Location {

src/bin/c08p07.rs

@@ -41,10 +41,10 @@ mod tests {
     fn test_permutations_without_dups() {
         let s1 = "abc";
         let permutations = vec!["abc", "bac", "bca", "acb", "cab", "cba"];
-        assert_eq!(permutations_without_dups(&s1), permutations);
+        assert_eq!(permutations_without_dups(s1), permutations);
 
         let s2 = "abcdefg";
-        let s2_perms = permutations_without_dups(&s2);
+        let s2_perms = permutations_without_dups(s2);
         let s2_set = hashset(&s2_perms);
         assert_eq!(s2_perms.len(), 5040);
         assert_eq!(s2_perms.len(), s2_set.len());
@@ -53,5 +53,5 @@ mod tests {
 
 fn main() {
     let s1 = "abc";
-    permutations_without_dups(&s1);
+    permutations_without_dups(s1);
 }

src/bin/c08p08.rs

@@ -34,11 +34,11 @@ mod tests {
     fn test_permutations_with_dups() {
         let s1 = "abb";
         let permutations = vec!["abb", "bab", "bba", "abb", "bab", "bba"];
-        assert_eq!(permutations_with_dups(&s1), permutations);
+        assert_eq!(permutations_with_dups(s1), permutations);
     }
 }
 
 fn main() {
     let s1 = "abc";
-    permutations_with_dups(&s1);
+    permutations_with_dups(s1);
 }

src/bin/c08p12.rs

@@ -6,7 +6,7 @@ fn check_valid(columns: &mut Vec<usize>, row1: usize, column1: usize) -> bool {
             return false;
         }
 
-        let column_distance = ((*column2 as i64) - (column1 as i64)).abs() as usize;
+        let column_distance = ((*column2 as i64) - (column1 as i64)).unsigned_abs() as usize;
 
         let row_distance = row1 - row2;
         if column_distance == row_distance {