Simplify From<Vec>

exercism#178 (comment)

Author: whit0694

exercises/bracket-push/example.rs

@@ -44,14 +44,8 @@ pub struct MatchingBrackets {
 }
 
 impl From<Vec<(char, char)>> for MatchingBrackets {
-    fn from(i: Vec<(char, char)>) -> Self {
-        let mut c: HashMap<char, char> = HashMap::new();
-
-        for (k, v) in i {
-            c.insert(k, v);
-        }
-
-        MatchingBrackets { collection: c }
+    fn from(v: Vec<(char, char)>) -> Self {
+        MatchingBrackets { collection: v.into_iter().collect::<HashMap<char, char>>() }
     }
 }