1 files changed, 4 insertions, 0 deletions
diff --git a/src/librustc_const_eval/eval.rs b/src/librustc_const_eval/eval.rs
index 418bd4b5eff..17a9454e9d4 100644
--- a/src/librustc_const_eval/eval.rs
+++ b/src/librustc_const_eval/eval.rs
@@ -328,6 +328,10 @@ fn eval_const_expr_partial<'a, 'tcx>(cx: &ConstContext<'a, 'tcx>,
                     return Ok(mk_const(Integral(Usize(ConstUsize::new(align,
                         tcx.sess.target.usize_ty).unwrap()))));
                 }
+                "type_id" => {
+                    let type_id = tcx.type_id_hash(substs.type_at(0));
+                    return Ok(mk_const(Integral(U64(type_id))));
+                }
                 _ => signal!(e, TypeckError)
             }
           }