diff --git a/src/librustc_mir/interpret/terminator.rs b/src/librustc_mir/interpret/terminator.rs
index 08d4ae34afb..ea8378574a3 100644
--- a/src/librustc_mir/interpret/terminator.rs
+++ b/src/librustc_mir/interpret/terminator.rs
@@ -311,9 +311,8 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                         // taking into account the `spread_arg`.  If we could write
                         // this is a single iterator (that handles `spread_arg`), then
                         // `pass_argument` would be the loop body. It takes care to
-                        // not advance `caller_iter` for ZSTs.
-                        let mut locals_iter = body.args_iter();
-                        while let Some(local) = locals_iter.next() {
+                        // not advance `caller_iter` for ZSTs
+                        for local in body.args_iter() {
                             let dest = self.eval_place(&mir::Place::from(local))?;
                             if Some(local) == body.spread_arg {
                                 // Must be a tuple
diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index ed007fe383c..805cd9d3e35 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -869,12 +869,8 @@ pub fn plain_summary_line(md: &str) -> String {
         }
     }
     let mut s = String::with_capacity(md.len() * 3 / 2);
-    let mut p = ParserWrapper { inner: Parser::new(md), is_in: 0, is_first: true };
-    while let Some(t) = p.next() {
-        if !t.is_empty() {
-            s.push_str(&t);
-        }
-    }
+    let p = ParserWrapper { inner: Parser::new(md), is_in: 0, is_first: true };
+    p.into_iter().filter(|t| !t.is_empty()).for_each(|i| s.push_str(&i));
     s
 }