From 47c97b1d5143e8504c2f4e10394efdda7d5cb1e6 Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Fri, 2 Feb 2024 21:23:13 +0000
Subject: [PATCH] Add rustdoc hack

---
 compiler/rustc_hir_analysis/src/coherence/builtin.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index 5a3878445937b..1cf9cc76e39f9 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -104,7 +104,12 @@ fn visit_implementation_of_copy(
             Err(infringing_fields_error(tcx, fields, LangItem::Copy, impl_did, span))
         }
         Err(CopyImplementationError::NotAnAdt) => {
-            Err(tcx.dcx().emit_err(errors::CopyImplOnNonAdt { span }))
+            if tcx.sess.opts.actually_rustdoc {
+                // HACK(rustdoc): `impl<Ret, T> Copy for fn(T) -> Ret` just for docs.
+                Ok(())
+            } else {
+                Err(tcx.dcx().emit_err(errors::CopyImplOnNonAdt { span }))
+            }
         }
         Err(CopyImplementationError::HasDestructor) => {
             Err(tcx.dcx().emit_err(errors::CopyImplOnTypeWithDtor { span }))