Rollup merge of #42251 - nikomatsakis:issue-42210-regr-unsized-tail, r=eddyb

extend `struct_tail` to operate over tuples

Not 100% sure why this got exposed when it wasn't before, but this struct definitely seems wrong.

Fixes #42110

r? @eddyb

1 files changed, 29 insertions, 0 deletions

diff --git a/src/test/run-pass/issue-42210.rs b/src/test/run-pass/issue-42210.rs
new file mode 100644
index 00000000000..ecdf78cd5bd
--- /dev/null
+++ b/src/test/run-pass/issue-42210.rs
@@ -0,0 +1,29 @@
+// Copyright 2014 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.
+
+// Regression test for #42210.
+
+// compile-flags: -g
+
+trait Foo {
+    fn foo() { }
+}
+
+struct Bar;
+
+trait Baz {
+}
+
+impl Foo for (Bar, Baz) { }
+
+
+fn main() {
+    <(Bar, Baz) as Foo>::foo()
+}