Use map_while

Author: camsteffen

src/visitor.rs

@@ -872,8 +872,7 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
         // Extract leading `use ...;`.
         let items: Vec<_> = stmts
             .iter()
-            .take_while(|stmt| stmt.to_item().map_or(false, is_use_item))
-            .filter_map(|stmt| stmt.to_item())
+            .map_while(|stmt| stmt.to_item().filter(|i| is_use_item(i)))
             .collect();
 
         if items.is_empty() {