From e0ddca95533b061ad1d57307785e56ecb839ea90 Mon Sep 17 00:00:00 2001
From: Tyler Mandry <tmandry@gmail.com>
Date: Sun, 17 Dec 2023 21:11:48 -0600
Subject: [PATCH 1/2] allow(async_fn_in_trait) on traits with Send variant

---
 trait-variant/examples/variant.rs | 11 +++++++++--
 trait-variant/src/variant.rs      | 22 ++++++++++++++++++----
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/trait-variant/examples/variant.rs b/trait-variant/examples/variant.rs
index 93c2ebe..5be07ef 100644
--- a/trait-variant/examples/variant.rs
+++ b/trait-variant/examples/variant.rs
@@ -10,8 +10,8 @@ use std::future::Future;
 
 use trait_variant::make_variant;
 
-#[make_variant(SendIntFactory: Send)]
-trait IntFactory {
+#[make_variant(IntFactory: Send)]
+pub trait LocalIntFactory {
     const NAME: &'static str;
 
     type MyFut<'a>: Future
@@ -24,4 +24,11 @@ trait IntFactory {
     fn another_async(&self, input: Result<(), &str>) -> Self::MyFut<'_>;
 }
 
+#[allow(dead_code)]
+fn spawn_task(factory: impl IntFactory + 'static) {
+    tokio::spawn(async move {
+        let _int = factory.make(1, "foo").await;
+    });
+}
+
 fn main() {}
diff --git a/trait-variant/src/variant.rs b/trait-variant/src/variant.rs
index 1a5bd1f..494a70c 100644
--- a/trait-variant/src/variant.rs
+++ b/trait-variant/src/variant.rs
@@ -56,15 +56,29 @@ pub fn make_variant(
     let attrs = parse_macro_input!(attr as Attrs);
     let item = parse_macro_input!(item as ItemTrait);
 
+    let maybe_allow_async_lint = if attrs
+        .variant
+        .bounds
+        .iter()
+        .any(|b| b.path.segments.last().unwrap().ident.to_string() == "Send")
+    {
+        quote! { #[allow(async_fn_in_trait)] }
+    } else {
+        quote! {}
+    };
+
     let variant = mk_variant(&attrs, &item);
     let blanket_impl = mk_blanket_impl(&attrs, &item);
-    let output = quote! {
+
+    quote! {
+        #maybe_allow_async_lint
         #item
+
         #variant
-        #blanket_impl
-    };
 
-    output.into()
+        #blanket_impl
+    }
+    .into()
 }
 
 fn mk_variant(attrs: &Attrs, tr: &ItemTrait) -> TokenStream {

From f1936772a9cc5a9d1cde38392a4923c972d0669c Mon Sep 17 00:00:00 2001
From: Travis Cross <tc@traviscross.com>
Date: Mon, 18 Dec 2023 09:45:37 +0000
Subject: [PATCH 2/2] Remove unneeded `to_string` call

In `syn`, there is a `PartialEq` impl for `Ident` that allows values
of this type to be compared directly against strings without calling
`to_string`, so let's do that.
---
 trait-variant/src/variant.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/trait-variant/src/variant.rs b/trait-variant/src/variant.rs
index 494a70c..8280599 100644
--- a/trait-variant/src/variant.rs
+++ b/trait-variant/src/variant.rs
@@ -60,7 +60,7 @@ pub fn make_variant(
         .variant
         .bounds
         .iter()
-        .any(|b| b.path.segments.last().unwrap().ident.to_string() == "Send")
+        .any(|b| b.path.segments.last().unwrap().ident == "Send")
     {
         quote! { #[allow(async_fn_in_trait)] }
     } else {