1 files changed, 46 insertions, 0 deletions
diff --git a/third_party/rust/zerocopy-derive/tests/enum_known_layout.rs b/third_party/rust/zerocopy-derive/tests/enum_known_layout.rs
new file mode 100644
index 0000000000..49a6765e53
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/enum_known_layout.rs
@@ -0,0 +1,46 @@
+// Copyright 2022 The Fuchsia Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#![allow(warnings)]
+
+mod util;
+
+use {core::marker::PhantomData, static_assertions::assert_impl_all, zerocopy::KnownLayout};
+
+#[derive(KnownLayout)]
+enum Foo {
+    A,
+}
+
+assert_impl_all!(Foo: KnownLayout);
+
+#[derive(KnownLayout)]
+enum Bar {
+    A = 0,
+}
+
+assert_impl_all!(Bar: KnownLayout);
+
+#[derive(KnownLayout)]
+enum Baz {
+    A = 1,
+    B = 0,
+}
+
+assert_impl_all!(Baz: KnownLayout);
+
+// Deriving `KnownLayout` should work if the enum has bounded parameters.
+
+#[derive(KnownLayout)]
+#[repr(C)]
+enum WithParams<'a: 'b, 'b: 'a, const N: usize, T: 'a + 'b + KnownLayout>
+where
+    'a: 'b,
+    'b: 'a,
+    T: 'a + 'b + KnownLayout,
+{
+    Variant([T; N], PhantomData<&'a &'b ()>),
+}
+
+assert_impl_all!(WithParams<'static, 'static, 42, u8>: KnownLayout);