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 956123d2ecdffaec49ed6424d713abeb0e4e4dc1 Mon Sep 17 00:00:00 2001
From: Tyler Mandry <tmandry@gmail.com>
Date: Sun, 17 Dec 2023 22:37:55 -0600
Subject: [PATCH 2/2] Shorten name to trait_variant::make

---
 README.md                         | 8 ++++----
 trait-variant/examples/variant.rs | 4 +---
 trait-variant/src/lib.rs          | 4 ++--
 trait-variant/src/variant.rs      | 2 +-
 4 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index f95a4eb..d2a3e44 100644
--- a/README.md
+++ b/README.md
@@ -2,12 +2,12 @@
 
 Utilities for working with impl traits in Rust.
 
-## `make_variant`
+## `trait_variant`
 
-`make_variant` generates a specialized version of a base trait that uses `async fn` and/or `-> impl Trait`. For example, if you want a `Send`able version of your trait, you'd write:
+`trait_variant` generates a specialized version of a base trait that uses `async fn` and/or `-> impl Trait`. For example, if you want a `Send`able version of your trait, you'd write:
 
 ```rust
-#[trait_variant::make_variant(SendIntFactory: Send)]
+#[trait_variant::make(SendIntFactory: Send)]
 trait IntFactory {
     async fn make(&self) -> i32;
     // ..or..
@@ -22,7 +22,7 @@ Implementers of the trait can choose to implement the variant instead of the ori
 
 ## `trait_transformer`
 
-`trait_transformer` does the same thing as `make_variant`, but using experimental nightly-only syntax that depends on the `return_type_notation` feature. It may be used to experiment with new kinds of trait transformations in the future.
+`trait_transformer` does the same thing as `make`, but using experimental nightly-only syntax that depends on the `return_type_notation` feature. It may be used to experiment with new kinds of trait transformations in the future.
 
 #### License and usage notes
 
diff --git a/trait-variant/examples/variant.rs b/trait-variant/examples/variant.rs
index 5be07ef..9c15409 100644
--- a/trait-variant/examples/variant.rs
+++ b/trait-variant/examples/variant.rs
@@ -8,9 +8,7 @@
 
 use std::future::Future;
 
-use trait_variant::make_variant;
-
-#[make_variant(IntFactory: Send)]
+#[trait_variant::make(IntFactory: Send)]
 pub trait LocalIntFactory {
     const NAME: &'static str;
 
diff --git a/trait-variant/src/lib.rs b/trait-variant/src/lib.rs
index 2694318..f651249 100644
--- a/trait-variant/src/lib.rs
+++ b/trait-variant/src/lib.rs
@@ -20,9 +20,9 @@ pub fn trait_transformer(
 }
 
 #[proc_macro_attribute]
-pub fn make_variant(
+pub fn make(
     attr: proc_macro::TokenStream,
     item: proc_macro::TokenStream,
 ) -> proc_macro::TokenStream {
-    variant::make_variant(attr, item)
+    variant::make(attr, item)
 }
diff --git a/trait-variant/src/variant.rs b/trait-variant/src/variant.rs
index 494a70c..74efcc1 100644
--- a/trait-variant/src/variant.rs
+++ b/trait-variant/src/variant.rs
@@ -49,7 +49,7 @@ impl Parse for MakeVariant {
     }
 }
 
-pub fn make_variant(
+pub fn make(
     attr: proc_macro::TokenStream,
     item: proc_macro::TokenStream,
 ) -> proc_macro::TokenStream {