From 186d148b4cd67223fde15b421086e74a95501096 Mon Sep 17 00:00:00 2001
From: Dylan MacKenzie <ecstaticmorse@gmail.com>
Date: Tue, 22 Sep 2020 10:21:58 -0700
Subject: [PATCH] Use correct feature gate for unsizing casts

---
 compiler/rustc_mir/src/transform/check_consts/ops.rs | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/compiler/rustc_mir/src/transform/check_consts/ops.rs b/compiler/rustc_mir/src/transform/check_consts/ops.rs
index b35c041ef53..e14dcf92b89 100644
--- a/compiler/rustc_mir/src/transform/check_consts/ops.rs
+++ b/compiler/rustc_mir/src/transform/check_consts/ops.rs
@@ -523,11 +523,7 @@ impl NonConstOp for UnionAccess {
 pub struct UnsizingCast;
 impl NonConstOp for UnsizingCast {
     fn status_in_item(&self, ccx: &ConstCx<'_, '_>) -> Status {
-        if ccx.const_kind() != hir::ConstContext::ConstFn {
-            Status::Allowed
-        } else {
-            Status::Unstable(sym::const_fn_transmute)
-        }
+        mcf_status_in_item(ccx)
     }
 
     fn emit_error(&self, ccx: &ConstCx<'_, '_>, span: Span) {