From c6c2f11ab614e5e17ddbfa28b5ff9c9e5a2d8b52 Mon Sep 17 00:00:00 2001
From: Santiago Pastorino <spastorino@gmail.com>
Date: Fri, 20 Aug 2021 18:32:57 -0300
Subject: [PATCH] Test tait use in a fn type

---
 .../type-alias-impl-trait-fn-type.rs                | 13 +++++++++++++
 .../type-alias-impl-trait-fn-type.stderr            |  9 +++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 src/test/ui/type-alias-impl-trait/type-alias-impl-trait-fn-type.rs
 create mode 100644 src/test/ui/type-alias-impl-trait/type-alias-impl-trait-fn-type.stderr

diff --git a/src/test/ui/type-alias-impl-trait/type-alias-impl-trait-fn-type.rs b/src/test/ui/type-alias-impl-trait/type-alias-impl-trait-fn-type.rs
new file mode 100644
index 0000000000000..299bdf562dc41
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/type-alias-impl-trait-fn-type.rs
@@ -0,0 +1,13 @@
+#![feature(type_alias_impl_trait)]
+#![allow(dead_code)]
+
+// FIXME: this is ruled out for now but should work
+
+type Foo = fn() -> impl Send;
+//~^ ERROR: `impl Trait` not allowed outside of function and method return types
+
+fn make_foo() -> Foo {
+    || 15
+}
+
+fn main() {}
diff --git a/src/test/ui/type-alias-impl-trait/type-alias-impl-trait-fn-type.stderr b/src/test/ui/type-alias-impl-trait/type-alias-impl-trait-fn-type.stderr
new file mode 100644
index 0000000000000..1c5d57d4af761
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/type-alias-impl-trait-fn-type.stderr
@@ -0,0 +1,9 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/type-alias-impl-trait-fn-type.rs:6:20
+   |
+LL | type Foo = fn() -> impl Send;
+   |                    ^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.