From e2decb908053fbca3520317b2ad9d0ecf42cc704 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Wed, 13 Sep 2023 19:32:02 +0000
Subject: [PATCH] Deprecate E0706

---
 compiler/rustc_ast_lowering/src/errors.rs           | 11 -----------
 compiler/rustc_error_codes/src/error_codes/E0706.md |  6 ++++--
 2 files changed, 4 insertions(+), 13 deletions(-)

diff --git a/compiler/rustc_ast_lowering/src/errors.rs b/compiler/rustc_ast_lowering/src/errors.rs
index a63bd4f8a0255..fe0c7d101c19c 100644
--- a/compiler/rustc_ast_lowering/src/errors.rs
+++ b/compiler/rustc_ast_lowering/src/errors.rs
@@ -354,17 +354,6 @@ pub struct InclusiveRangeWithNoEnd {
     pub span: Span,
 }
 
-#[derive(Diagnostic, Clone, Copy)]
-#[diag(ast_lowering_trait_fn_async, code = "E0706")]
-#[note]
-#[note(ast_lowering_note2)]
-pub struct TraitFnAsync {
-    #[primary_span]
-    pub fn_span: Span,
-    #[label]
-    pub span: Span,
-}
-
 #[derive(Diagnostic)]
 pub enum BadReturnTypeNotation {
     #[diag(ast_lowering_bad_return_type_notation_inputs)]
diff --git a/compiler/rustc_error_codes/src/error_codes/E0706.md b/compiler/rustc_error_codes/src/error_codes/E0706.md
index fabd855a222f0..a09abb59ba8c9 100644
--- a/compiler/rustc_error_codes/src/error_codes/E0706.md
+++ b/compiler/rustc_error_codes/src/error_codes/E0706.md
@@ -1,8 +1,10 @@
+#### Note: this error code is no longer emitted by the compiler.
+
 `async fn`s are not yet supported in traits in Rust.
 
 Erroneous code example:
 
-```compile_fail,edition2018
+```ignore,edition2018
 trait T {
     // Neither case is currently supported.
     async fn foo() {}
@@ -13,7 +15,7 @@ trait T {
 `async fn`s return an `impl Future`, making the following two examples
 equivalent:
 
-```edition2018,ignore (example-of-desugaring-equivalence)
+```ignore,edition2018 (example-of-desugaring-equivalence)
 async fn foo() -> User {
     unimplemented!()
 }