From 22baa46f784856b6d6bb4374bcc3fb4b66bb8097 Mon Sep 17 00:00:00 2001
From: Garming Sam <garming_sam@outlook.com>
Date: Mon, 10 Aug 2015 04:45:57 +1200
Subject: [PATCH] Avoid adding extra paren with two casts

---
 src/libsyntax/print/pprust.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index d59ab2ba565c..7919bd45ced5 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -1753,7 +1753,11 @@ impl<'a> State<'a> {
                 try!(self.print_literal(&**lit));
             }
             ast::ExprCast(ref expr, ref ty) => {
-                try!(self.print_expr_maybe_paren(&**expr));
+                if let ast::ExprCast(..) = expr.node {
+                    try!(self.print_expr(&**expr));
+                } else {
+                    try!(self.print_expr_maybe_paren(&**expr));
+                }
                 try!(space(&mut self.s));
                 try!(self.word_space("as"));
                 try!(self.print_type(&**ty));