From d913af8691d4002166c9a6e1b60e51407cf82c9c Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Wed, 21 Mar 2018 06:31:39 -0400
Subject: [PATCH] add new test for `dyn<Trait + '_>` used in a struct

`'_` is illegal in structs; this currently gets a duplicate error
---
 .../dyn-trait-underscore-in-struct.rs         | 26 +++++++++++++++++++
 .../dyn-trait-underscore-in-struct.stderr     | 16 ++++++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 src/test/ui/underscore-lifetime/dyn-trait-underscore-in-struct.rs
 create mode 100644 src/test/ui/underscore-lifetime/dyn-trait-underscore-in-struct.stderr

diff --git a/src/test/ui/underscore-lifetime/dyn-trait-underscore-in-struct.rs b/src/test/ui/underscore-lifetime/dyn-trait-underscore-in-struct.rs
new file mode 100644
index 00000000000..d10541ad33b
--- /dev/null
+++ b/src/test/ui/underscore-lifetime/dyn-trait-underscore-in-struct.rs
@@ -0,0 +1,26 @@
+// Copyright 2015 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.
+
+// Check that the `'_` in `dyn Trait + '_` acts like ordinary elision,
+// and not like an object lifetime default.
+//
+// cc #48468
+
+#![feature(dyn_trait)]
+#![feature(underscore_lifetimes)]
+
+use std::fmt::Debug;
+
+struct Foo {
+    x: Box<dyn Debug + '_>, //~ ERROR missing lifetime specifier
+    //~^ ERROR E0228
+}
+
+fn main() { }
diff --git a/src/test/ui/underscore-lifetime/dyn-trait-underscore-in-struct.stderr b/src/test/ui/underscore-lifetime/dyn-trait-underscore-in-struct.stderr
new file mode 100644
index 00000000000..a88ecb18dd6
--- /dev/null
+++ b/src/test/ui/underscore-lifetime/dyn-trait-underscore-in-struct.stderr
@@ -0,0 +1,16 @@
+error[E0106]: missing lifetime specifier
+  --> $DIR/dyn-trait-underscore-in-struct.rs:22:24
+   |
+LL |     x: Box<dyn Debug + '_>, //~ ERROR missing lifetime specifier
+   |                        ^^ expected lifetime parameter
+
+error[E0228]: the lifetime bound for this object type cannot be deduced from context; please supply an explicit bound
+  --> $DIR/dyn-trait-underscore-in-struct.rs:22:12
+   |
+LL |     x: Box<dyn Debug + '_>, //~ ERROR missing lifetime specifier
+   |            ^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
+Some errors occurred: E0106, E0228.
+For more information about an error, try `rustc --explain E0106`.