regex_set: Derive Default instead of manually implementing it.

Author: emilio

src/regex_set.rs

@@ -4,7 +4,7 @@ use regex::RegexSet as RxSet;
 use std::cell::Cell;
 
 /// A dynamic set of regular expressions.
-#[derive(Debug)]
+#[derive(Debug, Default)]
 pub struct RegexSet {
     items: Vec<String>,
     matched: Vec<Cell<bool>>,
@@ -76,13 +76,3 @@ impl RegexSet {
         false
     }
 }
-
-impl Default for RegexSet {
-    fn default() -> Self {
-        RegexSet {
-            items: vec![],
-            matched: vec![],
-            set: None,
-        }
-    }
-}