From 1474face6fe8081c29c79179460e1b3e53f51a6e Mon Sep 17 00:00:00 2001
From: Wesley Wiser <wwiser@gmail.com>
Date: Fri, 24 Apr 2020 20:27:17 -0400
Subject: [PATCH] Add regression test for #26376

---
 .../unsized/return-unsized-from-trait-method.rs  | 16 ++++++++++++++++
 .../return-unsized-from-trait-method.stderr      |  9 +++++++++
 2 files changed, 25 insertions(+)
 create mode 100644 src/test/ui/unsized/return-unsized-from-trait-method.rs
 create mode 100644 src/test/ui/unsized/return-unsized-from-trait-method.stderr

diff --git a/src/test/ui/unsized/return-unsized-from-trait-method.rs b/src/test/ui/unsized/return-unsized-from-trait-method.rs
new file mode 100644
index 0000000000000..2d265d5db5c14
--- /dev/null
+++ b/src/test/ui/unsized/return-unsized-from-trait-method.rs
@@ -0,0 +1,16 @@
+// ignore-tidy-linelength
+
+// regression test for #26376
+
+trait Foo {
+    fn foo(&self) -> [u8];
+}
+
+fn foo(f: Option<&dyn Foo>) {
+    if let Some(f) = f {
+        let _ = f.foo();
+        //~^ ERROR cannot move a value of type [u8]: the size of [u8] cannot be statically determined
+    }
+}
+
+fn main() { foo(None) }
diff --git a/src/test/ui/unsized/return-unsized-from-trait-method.stderr b/src/test/ui/unsized/return-unsized-from-trait-method.stderr
new file mode 100644
index 0000000000000..7ecdd28616674
--- /dev/null
+++ b/src/test/ui/unsized/return-unsized-from-trait-method.stderr
@@ -0,0 +1,9 @@
+error[E0161]: cannot move a value of type [u8]: the size of [u8] cannot be statically determined
+  --> $DIR/return-unsized-from-trait-method.rs:11:17
+   |
+LL |         let _ = f.foo();
+   |                 ^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0161`.