codewide: appease Clippy

Author: wprzytula

content/lessons/03_data_types/option.rs

@@ -48,8 +48,8 @@ fn main() {
     assert_eq!(number.checked_div(2), Some(21));
     assert_eq!(number.checked_div(0), None);
 
-    // Now let's imagine we search for a value in a vector
-    let numbers = vec![1, 2, 3, 4, 5];
+    // Now let's imagine we search for a value in an array.
+    let numbers = [1, 2, 3, 4, 5];
     let three = numbers.iter().copied().find(|&x| x == 3);
     assert_eq!(three, Some(3));
     let seven = numbers.iter().copied().find(|&x| x == 7);

content/lessons/07_smart_pointers/weak_ref.rs

@@ -32,5 +32,5 @@ fn main() {
     }
 
     println!("The value should be deallocated by now.");
-    matches!(weak_ref.upgrade(), None);
+    assert!(weak_ref.upgrade().is_none());
 }