Check functions predicates

src/test/compile-fail/nll/where_clauses_in_functions.rs

@@ -0,0 +1,28 @@
+// Copyright 2017 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.
+
+// compile-flags: -Z borrowck=mir -Z nll
+
+#![allow(dead_code)]
+
+fn foo<'a, 'b>(x: &'a u32, y: &'b u32) -> (&'a u32, &'b u32)
+where
+    'a: 'b,
+{
+    (x, y)
+}
+
+fn bar<'a, 'b>(x: &'a u32, y: &'b u32) -> (&'a u32, &'b u32) {
+    foo(x, y)
+    //~^ ERROR free region `'_#1r` does not outlive free region `'_#2r`
+    //~| WARNING not reporting region error due to -Znll
+}
+
+fn main() {}