From 13d284d177fb48db15be929c8999e45d1b04802e Mon Sep 17 00:00:00 2001
From: Eric Holk <ericholk@microsoft.com>
Date: Thu, 30 Nov 2023 16:39:56 -0800
Subject: [PATCH] Option<CoroutineKind>

---
 src/closures.rs | 13 +++++++++----
 src/items.rs    |  5 +++--
 src/utils.rs    |  1 -
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/closures.rs b/src/closures.rs
index 23cd6e4c092..d79218e78ee 100644
--- a/src/closures.rs
+++ b/src/closures.rs
@@ -29,7 +29,7 @@ pub(crate) fn rewrite_closure(
     binder: &ast::ClosureBinder,
     constness: ast::Const,
     capture: ast::CaptureBy,
-    coro_kind: &ast::CoroutineKind,
+    coro_kind: &Option<ast::CoroutineKind>,
     movability: ast::Movability,
     fn_decl: &ast::FnDecl,
     body: &ast::Expr,
@@ -233,7 +233,7 @@ fn rewrite_closure_fn_decl(
     binder: &ast::ClosureBinder,
     constness: ast::Const,
     capture: ast::CaptureBy,
-    coro_kind: &ast::CoroutineKind,
+    coro_kind: &Option<ast::CoroutineKind>,
     movability: ast::Movability,
     fn_decl: &ast::FnDecl,
     body: &ast::Expr,
@@ -263,8 +263,13 @@ fn rewrite_closure_fn_decl(
     } else {
         ""
     };
-    let is_async = if coro_kind.is_async() { "async " } else { "" };
-    let is_gen = if coro_kind.is_gen() { "gen " } else { "" };
+    let (is_async, is_gen) = if let Some(coro_kind) = coro_kind {
+        let is_async = if coro_kind.is_async() { "async " } else { "" };
+        let is_gen = if coro_kind.is_gen() { "gen " } else { "" };
+        (is_async, is_gen)
+    } else {
+        ("", "")
+    };
     let mover = if matches!(capture, ast::CaptureBy::Value { .. }) {
         "move "
     } else {
diff --git a/src/items.rs b/src/items.rs
index 0a1f823fe87..4dff65f8cd0 100644
--- a/src/items.rs
+++ b/src/items.rs
@@ -287,7 +287,7 @@ pub(crate) struct FnSig<'a> {
     decl: &'a ast::FnDecl,
     generics: &'a ast::Generics,
     ext: ast::Extern,
-    coro_kind: Cow<'a, ast::CoroutineKind>,
+    coro_kind: Cow<'a, Option<ast::CoroutineKind>>,
     constness: ast::Const,
     defaultness: ast::Defaultness,
     unsafety: ast::Unsafe,
@@ -343,7 +343,8 @@ fn to_str(&self, context: &RewriteContext<'_>) -> String {
         result.push_str(&*format_visibility(context, self.visibility));
         result.push_str(format_defaultness(self.defaultness));
         result.push_str(format_constness(self.constness));
-        result.push_str(format_coro(&self.coro_kind));
+        self.coro_kind
+            .map(|coro_kind| result.push_str(format_coro(&coro_kind)));
         result.push_str(format_unsafety(self.unsafety));
         result.push_str(&format_extern(
             self.ext,
diff --git a/src/utils.rs b/src/utils.rs
index 18d8f0cdbd7..5805e417c04 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -79,7 +79,6 @@ pub(crate) fn format_coro(coro_kind: &ast::CoroutineKind) -> &'static str {
     match coro_kind {
         ast::CoroutineKind::Async { .. } => "async ",
         ast::CoroutineKind::Gen { .. } => "gen ",
-        ast::CoroutineKind::None => "",
     }
 }