From 0de72bba3634efb9d7b637b274c8f2ec1a335bf4 Mon Sep 17 00:00:00 2001
From: Oliver Schneider <git-spam-no-reply9815368754983@oli-obk.de>
Date: Tue, 21 Jun 2016 10:08:31 +0200
Subject: [PATCH] don't warn on casting byte strs to slices

---
 src/librustc_const_eval/eval.rs          |  1 +
 src/test/run-pass/const-byte-str-cast.rs | 15 +++++++++++++++
 2 files changed, 16 insertions(+)
 create mode 100644 src/test/run-pass/const-byte-str-cast.rs

diff --git a/src/librustc_const_eval/eval.rs b/src/librustc_const_eval/eval.rs
index 7551bc5c234ef..34dce44004823 100644
--- a/src/librustc_const_eval/eval.rs
+++ b/src/librustc_const_eval/eval.rs
@@ -1116,6 +1116,7 @@ fn cast_const<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, val: ConstVal, ty: ty::Ty)
             ty::TyRawPtr(_) => {
                 Err(ErrKind::UnimplementedConstVal("casting a bytestr to a raw ptr"))
             },
+            ty::TyRef(..) => Err(ErrKind::UnimplementedConstVal("casting a bytestr to slice")),
             _ => Err(CannotCast),
         },
         _ => Err(CannotCast),
diff --git a/src/test/run-pass/const-byte-str-cast.rs b/src/test/run-pass/const-byte-str-cast.rs
new file mode 100644
index 0000000000000..2f265b9112b98
--- /dev/null
+++ b/src/test/run-pass/const-byte-str-cast.rs
@@ -0,0 +1,15 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#[deny(warnings)]
+
+pub fn main() {
+    let _ = b"x" as &[u8];
+}