Merge pull request #526 from asomers/rpitit

Add a test for the Return Position Impl Trait in Trait feature

mockall/tests/automock_rpitit.rs

@@ -0,0 +1,22 @@
+// vim: tw=80
+//! Return position Impl Trait in Traits
+//! https://rust-lang.github.io/rfcs/3425-return-position-impl-trait-in-traits.html
+#![cfg(feature = "nightly")]
+#![deny(warnings)]
+
+use std::fmt::Debug;
+
+use mockall::*;
+
+#[automock]
+trait Foo {
+    fn bar(&self) -> impl Debug;
+}
+
+#[test]
+fn returning() {
+    let mut foo = MockFoo::default();
+    foo.expect_bar()
+        .returning(|| Box::new(42u32));
+    assert_eq!("42", format!("{:?}", foo.bar()));
+}