diff --git a/src/expr.rs b/src/expr.rs
index d1303d95276..e7418562770 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -63,7 +63,7 @@ pub fn format_expr(
 
     let expr_rw = match expr.node {
         ast::ExprKind::Array(ref expr_vec) => rewrite_array(
-            expr_vec.iter().map(|e| &**e),
+            &ptr_vec_to_ref_vec(expr_vec),
             mk_sp(context.codemap.span_after(expr.span, "["), expr.span.hi()),
             context,
             shape,
@@ -397,16 +397,13 @@ where
     ))
 }
 
-pub fn rewrite_array<'a, I>(
-    expr_iter: I,
+pub fn rewrite_array<T: Rewrite + Spanned + ToExpr>(
+    exprs: &[&T],
     span: Span,
     context: &RewriteContext,
     shape: Shape,
     trailing_comma: bool,
-) -> Option<String>
-where
-    I: Iterator<Item = &'a ast::Expr>,
-{
+) -> Option<String> {
     let bracket_size = if context.config.spaces_within_parens_and_brackets() {
         2 // "[ "
     } else {
@@ -426,11 +423,11 @@ where
 
     let items = itemize_list(
         context.codemap,
-        expr_iter,
+        exprs.iter(),
         "]",
         ",",
-        |item| item.span.lo(),
-        |item| item.span.hi(),
+        |item| item.span().lo(),
+        |item| item.span().hi(),
         |item| item.rewrite(context, nested_shape),
         span.lo(),
         span.hi(),
diff --git a/src/macros.rs b/src/macros.rs
index 8c8b50b7ca3..6d115e155d0 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -255,24 +255,14 @@ pub fn rewrite_macro(
                     trailing_comma = false;
                 }
                 // Convert `MacroArg` into `ast::Expr`, as `rewrite_array` only accepts the latter.
-                let expr_vec: Vec<_> = arg_vec
-                    .iter()
-                    .filter_map(|e| match *e {
-                        MacroArg::Expr(ref e) => Some(e.clone()),
-                        _ => None,
-                    })
-                    .collect();
-                if expr_vec.len() != arg_vec.len() {
-                    return Some(context.snippet(mac.span));
-                }
                 let sp = mk_sp(
                     context
                         .codemap
                         .span_after(mac.span, original_style.opener()),
                     mac.span.hi() - BytePos(1),
                 );
-                let rewrite =
-                    rewrite_array(expr_vec.iter(), sp, context, mac_shape, trailing_comma)?;
+                let arg_vec = &arg_vec.iter().map(|e| &*e).collect::<Vec<_>>()[..];
+                let rewrite = rewrite_array(arg_vec, sp, context, mac_shape, trailing_comma)?;
 
                 Some(format!("{}{}", macro_name, rewrite))
             }