From 693211ad7017493278a8030433286c2df052e316 Mon Sep 17 00:00:00 2001
From: Bryan Garza <1396101+bryangarza@users.noreply.github.com>
Date: Thu, 29 Jun 2023 15:01:39 -0700
Subject: [PATCH] Enable co-induction support for Safe Transmute

This patch adds the `#[rustc_coinductive]` annotation to
`BikeshedIntrinsicFrom`, so that it's possible to compute transmutability for
recursive types.
---
 core/src/mem/transmutability.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/core/src/mem/transmutability.rs b/core/src/mem/transmutability.rs
index 3805d149b..aed23119f 100644
--- a/core/src/mem/transmutability.rs
+++ b/core/src/mem/transmutability.rs
@@ -9,6 +9,7 @@ use crate::marker::ConstParamTy;
 #[lang = "transmute_trait"]
 #[cfg_attr(not(bootstrap), rustc_deny_explicit_impl(implement_via_object = false))]
 #[cfg_attr(bootstrap, rustc_deny_explicit_impl)]
+#[rustc_coinductive]
 pub unsafe trait BikeshedIntrinsicFrom<Src, Context, const ASSUME: Assume = { Assume::NOTHING }>
 where
     Src: ?Sized,