Import async-trait crate.
Bug: 164106399
Bug: 158290206
Test: mm
Change-Id: I0c4a491b785134e4ac1d5572e5ff94b8699dc0bc
diff --git a/tests/test.rs b/tests/test.rs
new file mode 100644
index 0000000..3ea2d15
--- /dev/null
+++ b/tests/test.rs
@@ -0,0 +1,961 @@
+#![cfg_attr(async_trait_nightly_testing, feature(specialization, const_generics))]
+
+use async_trait::async_trait;
+
+pub mod executor;
+
+// Dummy module to check that the expansion refer to rust's core crate
+mod core {}
+
+#[async_trait]
+trait Trait {
+ type Assoc;
+
+ async fn selfvalue(self)
+ where
+ Self: Sized,
+ {
+ }
+
+ async fn selfref(&self) {}
+
+ async fn selfmut(&mut self) {}
+
+ async fn required() -> Self::Assoc;
+
+ async fn elided_lifetime(_x: &str) {}
+
+ async fn explicit_lifetime<'a>(_x: &'a str) {}
+
+ async fn generic_type_param<T: Send>(x: Box<T>) -> T {
+ *x
+ }
+
+ async fn calls(&self) {
+ self.selfref().await;
+ Self::elided_lifetime("").await;
+ <Self>::elided_lifetime("").await;
+ }
+
+ async fn calls_mut(&mut self) {
+ self.selfmut().await;
+ }
+}
+
+struct Struct;
+
+#[async_trait]
+impl Trait for Struct {
+ type Assoc = ();
+
+ async fn selfvalue(self) {}
+
+ async fn selfref(&self) {}
+
+ async fn selfmut(&mut self) {}
+
+ async fn required() -> Self::Assoc {}
+
+ async fn elided_lifetime(_x: &str) {}
+
+ async fn explicit_lifetime<'a>(_x: &'a str) {}
+
+ async fn generic_type_param<T: Send>(x: Box<T>) -> T {
+ *x
+ }
+
+ async fn calls(&self) {
+ self.selfref().await;
+ Self::elided_lifetime("").await;
+ <Self>::elided_lifetime("").await;
+ }
+
+ async fn calls_mut(&mut self) {
+ self.selfmut().await;
+ }
+}
+
+pub async fn test() {
+ let mut s = Struct;
+ s.selfref().await;
+ s.selfmut().await;
+ s.selfvalue().await;
+
+ Struct::required().await;
+ Struct::elided_lifetime("").await;
+ Struct::explicit_lifetime("").await;
+ Struct::generic_type_param(Box::new("")).await;
+
+ let mut s = Struct;
+ s.calls().await;
+ s.calls_mut().await;
+}
+
+pub async fn test_object_safe_without_default() {
+ #[async_trait]
+ trait ObjectSafe {
+ async fn f(&self);
+ }
+
+ #[async_trait]
+ impl ObjectSafe for Struct {
+ async fn f(&self) {}
+ }
+
+ let object = &Struct as &dyn ObjectSafe;
+ object.f().await;
+}
+
+pub async fn test_object_safe_with_default() {
+ #[async_trait]
+ trait ObjectSafe: Sync {
+ async fn f(&self) {}
+ }
+
+ #[async_trait]
+ impl ObjectSafe for Struct {
+ async fn f(&self) {}
+ }
+
+ let object = &Struct as &dyn ObjectSafe;
+ object.f().await;
+}
+
+pub async fn test_object_no_send() {
+ #[async_trait(?Send)]
+ trait ObjectSafe: Sync {
+ async fn f(&self) {}
+ }
+
+ #[async_trait(?Send)]
+ impl ObjectSafe for Struct {
+ async fn f(&self) {}
+ }
+
+ let object = &Struct as &dyn ObjectSafe;
+ object.f().await;
+}
+
+#[async_trait]
+pub unsafe trait UnsafeTrait {}
+
+#[async_trait]
+unsafe impl UnsafeTrait for () {}
+
+#[async_trait]
+pub(crate) unsafe trait UnsafeTraitPubCrate {}
+
+#[async_trait]
+unsafe trait UnsafeTraitPrivate {}
+
+// https://github.com/dtolnay/async-trait/issues/1
+pub mod issue1 {
+ use async_trait::async_trait;
+
+ #[async_trait]
+ trait Issue1 {
+ async fn f<U>(&self);
+ }
+
+ #[async_trait]
+ impl<T: Sync> Issue1 for Vec<T> {
+ async fn f<U>(&self) {}
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/2
+pub mod issue2 {
+ use async_trait::async_trait;
+ use std::future::Future;
+
+ #[async_trait]
+ pub trait Issue2: Future {
+ async fn flatten(self) -> <Self::Output as Future>::Output
+ where
+ Self::Output: Future + Send,
+ Self: Sized,
+ {
+ let nested_future = self.await;
+ nested_future.await
+ }
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/9
+pub mod issue9 {
+ use async_trait::async_trait;
+
+ #[async_trait]
+ pub trait Issue9: Sized + Send {
+ async fn f(_x: Self) {}
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/11
+pub mod issue11 {
+ use async_trait::async_trait;
+ use std::sync::Arc;
+
+ #[async_trait]
+ trait Issue11 {
+ async fn example(self: Arc<Self>);
+ }
+
+ struct Struct;
+
+ #[async_trait]
+ impl Issue11 for Struct {
+ async fn example(self: Arc<Self>) {}
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/15
+pub mod issue15 {
+ use async_trait::async_trait;
+ use std::marker::PhantomData;
+
+ trait Trait {}
+
+ #[async_trait]
+ trait Issue15 {
+ async fn myfn(&self, _: PhantomData<dyn Trait + Send>) {}
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/17
+pub mod issue17 {
+ use async_trait::async_trait;
+
+ #[async_trait]
+ trait Issue17 {
+ async fn f(&self);
+ }
+
+ struct Struct {
+ string: String,
+ }
+
+ #[async_trait]
+ impl Issue17 for Struct {
+ async fn f(&self) {
+ println!("{}", self.string);
+ }
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/23
+pub mod issue23 {
+ use async_trait::async_trait;
+
+ #[async_trait]
+ pub trait Issue23 {
+ async fn f(self);
+
+ async fn g(mut self)
+ where
+ Self: Sized,
+ {
+ do_something(&mut self);
+ }
+ }
+
+ struct S {}
+
+ #[async_trait]
+ impl Issue23 for S {
+ async fn f(mut self) {
+ do_something(&mut self);
+ }
+ }
+
+ fn do_something<T>(_: &mut T) {}
+}
+
+// https://github.com/dtolnay/async-trait/issues/25
+#[cfg(async_trait_nightly_testing)]
+pub mod issue25 {
+ use crate::executor;
+ use async_trait::async_trait;
+ use std::fmt::{Display, Write};
+
+ #[async_trait]
+ trait AsyncToString {
+ async fn async_to_string(&self) -> String;
+ }
+
+ #[async_trait]
+ impl AsyncToString for String {
+ async fn async_to_string(&self) -> String {
+ "special".to_owned()
+ }
+ }
+
+ macro_rules! hide_from_stable_parser {
+ ($($tt:tt)*) => {
+ $($tt)*
+ };
+ }
+
+ hide_from_stable_parser! {
+ #[async_trait]
+ impl<T: ?Sized + Display + Sync> AsyncToString for T {
+ default async fn async_to_string(&self) -> String {
+ let mut buf = String::new();
+ buf.write_fmt(format_args!("{}", self)).unwrap();
+ buf
+ }
+ }
+ }
+
+ #[test]
+ fn test() {
+ let fut = true.async_to_string();
+ assert_eq!(executor::block_on_simple(fut), "true");
+
+ let string = String::new();
+ let fut = string.async_to_string();
+ assert_eq!(executor::block_on_simple(fut), "special");
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/28
+pub mod issue28 {
+ use async_trait::async_trait;
+
+ struct Str<'a>(&'a str);
+
+ #[async_trait]
+ trait Trait1<'a> {
+ async fn f(x: Str<'a>) -> &'a str;
+ async fn g(x: Str<'a>) -> &'a str {
+ x.0
+ }
+ }
+
+ #[async_trait]
+ impl<'a> Trait1<'a> for str {
+ async fn f(x: Str<'a>) -> &'a str {
+ x.0
+ }
+ }
+
+ #[async_trait]
+ trait Trait2 {
+ async fn f();
+ }
+
+ #[async_trait]
+ impl<'a> Trait2 for &'a () {
+ async fn f() {}
+ }
+
+ #[async_trait]
+ trait Trait3<'a, 'b> {
+ async fn f(_: &'a &'b ()); // chain 'a and 'b
+ async fn g(_: &'b ()); // chain 'b only
+ async fn h(); // do not chain
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/31
+pub mod issue31 {
+ use async_trait::async_trait;
+
+ pub struct Struct<'a> {
+ pub name: &'a str,
+ }
+
+ #[async_trait]
+ pub trait Trait<'a> {
+ async fn hello(thing: Struct<'a>) -> String;
+ async fn hello_twice(one: Struct<'a>, two: Struct<'a>) -> String {
+ let str1 = Self::hello(one).await;
+ let str2 = Self::hello(two).await;
+ str1 + &str2
+ }
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/42
+pub mod issue42 {
+ use async_trait::async_trait;
+
+ #[async_trait]
+ pub trait Context: Sized {
+ async fn from_parts() -> Self;
+ }
+
+ pub struct TokenContext;
+
+ #[async_trait]
+ impl Context for TokenContext {
+ async fn from_parts() -> TokenContext {
+ TokenContext
+ }
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/44
+pub mod issue44 {
+ use async_trait::async_trait;
+
+ #[async_trait]
+ pub trait StaticWithWhereSelf
+ where
+ Box<Self>: Sized,
+ Self: Sized + Send,
+ {
+ async fn get_one() -> u8 {
+ 1
+ }
+ }
+
+ pub struct Struct;
+
+ #[async_trait]
+ impl StaticWithWhereSelf for Struct {}
+}
+
+// https://github.com/dtolnay/async-trait/issues/45
+pub mod issue45 {
+ use crate::executor;
+ use async_trait::async_trait;
+ use std::fmt::Debug;
+ use std::sync::atomic::{AtomicU64, Ordering};
+ use std::sync::{Arc, Mutex};
+ use tracing::event::Event;
+ use tracing::field::{Field, Visit};
+ use tracing::span::{Attributes, Id, Record};
+ use tracing::{info, instrument, subscriber, Metadata, Subscriber};
+
+ #[async_trait]
+ pub trait Parent {
+ async fn foo(&mut self, v: usize);
+ }
+
+ #[async_trait]
+ pub trait Child {
+ async fn bar(&self);
+ }
+
+ #[derive(Debug)]
+ struct Impl(usize);
+
+ #[async_trait]
+ impl Parent for Impl {
+ #[instrument]
+ async fn foo(&mut self, v: usize) {
+ self.0 = v;
+ self.bar().await;
+ }
+ }
+
+ #[async_trait]
+ impl Child for Impl {
+ // Let's check that tracing detects the renaming of the `self` variable
+ // too, as tracing::instrument is not going to be able to skip the
+ // `self` argument if it can't find it in the function signature.
+ #[instrument(skip(self))]
+ async fn bar(&self) {
+ info!(val = self.0);
+ }
+ }
+
+ // A simple subscriber implementation to test the behavior of async-trait
+ // with tokio-rs/tracing. This implementation is not robust against race
+ // conditions, but it's not an issue here as we are only polling on a single
+ // future at a time.
+ #[derive(Debug)]
+ struct SubscriberInner {
+ current_depth: AtomicU64,
+ // We assert that nested functions work. If the fix were to break, we
+ // would see two top-level functions instead of `bar` nested in `foo`.
+ max_depth: AtomicU64,
+ max_span_id: AtomicU64,
+ // Name of the variable / value / depth when the event was recorded.
+ value: Mutex<Option<(&'static str, u64, u64)>>,
+ }
+
+ #[derive(Debug, Clone)]
+ struct TestSubscriber {
+ inner: Arc<SubscriberInner>,
+ }
+
+ impl TestSubscriber {
+ fn new() -> Self {
+ TestSubscriber {
+ inner: Arc::new(SubscriberInner {
+ current_depth: AtomicU64::new(0),
+ max_depth: AtomicU64::new(0),
+ max_span_id: AtomicU64::new(1),
+ value: Mutex::new(None),
+ }),
+ }
+ }
+ }
+
+ struct U64Visitor(Option<(&'static str, u64)>);
+
+ impl Visit for U64Visitor {
+ fn record_debug(&mut self, _field: &Field, _value: &dyn Debug) {}
+
+ fn record_u64(&mut self, field: &Field, value: u64) {
+ self.0 = Some((field.name(), value));
+ }
+ }
+
+ impl Subscriber for TestSubscriber {
+ fn enabled(&self, _metadata: &Metadata) -> bool {
+ true
+ }
+ fn new_span(&self, _span: &Attributes) -> Id {
+ Id::from_u64(self.inner.max_span_id.fetch_add(1, Ordering::AcqRel))
+ }
+ fn record(&self, _span: &Id, _values: &Record) {}
+ fn record_follows_from(&self, _span: &Id, _follows: &Id) {}
+ fn event(&self, event: &Event) {
+ let mut visitor = U64Visitor(None);
+ event.record(&mut visitor);
+ if let Some((s, v)) = visitor.0 {
+ let current_depth = self.inner.current_depth.load(Ordering::Acquire);
+ *self.inner.value.lock().unwrap() = Some((s, v, current_depth));
+ }
+ }
+ fn enter(&self, _span: &Id) {
+ let old_depth = self.inner.current_depth.fetch_add(1, Ordering::AcqRel);
+ if old_depth + 1 > self.inner.max_depth.load(Ordering::Acquire) {
+ self.inner.max_depth.fetch_add(1, Ordering::AcqRel);
+ }
+ }
+ fn exit(&self, _span: &Id) {
+ self.inner.current_depth.fetch_sub(1, Ordering::AcqRel);
+ }
+ }
+
+ #[test]
+ fn tracing() {
+ // Create the future outside of the subscriber, as no call to tracing
+ // should be made until the future is polled.
+ let mut struct_impl = Impl(0);
+ let fut = struct_impl.foo(5);
+ let subscriber = TestSubscriber::new();
+ subscriber::with_default(subscriber.clone(), || executor::block_on_simple(fut));
+ // Did we enter bar inside of foo?
+ assert_eq!(subscriber.inner.max_depth.load(Ordering::Acquire), 2);
+ // Have we exited all spans?
+ assert_eq!(subscriber.inner.current_depth.load(Ordering::Acquire), 0);
+ // Did we create only two spans? Note: spans start at 1, hence the -1.
+ assert_eq!(subscriber.inner.max_span_id.load(Ordering::Acquire) - 1, 2);
+ // Was the value recorded at the right depth i.e. in the right function?
+ // If so, was it the expected value?
+ assert_eq!(*subscriber.inner.value.lock().unwrap(), Some(("val", 5, 2)));
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/46
+pub mod issue46 {
+ use async_trait::async_trait;
+
+ macro_rules! implement_commands_workaround {
+ ($tyargs:tt : $ty:tt) => {
+ #[async_trait]
+ pub trait AsyncCommands1: Sized {
+ async fn f<$tyargs: $ty>(&mut self, x: $tyargs) {
+ self.f(x).await
+ }
+ }
+ };
+ }
+
+ implement_commands_workaround!(K: Send);
+
+ macro_rules! implement_commands {
+ ($tyargs:ident : $ty:ident) => {
+ #[async_trait]
+ pub trait AsyncCommands2: Sized {
+ async fn f<$tyargs: $ty>(&mut self, x: $tyargs) {
+ self.f(x).await
+ }
+ }
+ };
+ }
+
+ implement_commands!(K: Send);
+}
+
+// https://github.com/dtolnay/async-trait/issues/53
+pub mod issue53 {
+ use async_trait::async_trait;
+
+ pub struct Unit;
+ pub struct Tuple(u8);
+ pub struct Struct {
+ pub x: u8,
+ }
+
+ #[async_trait]
+ pub trait Trait {
+ async fn method();
+ }
+
+ #[async_trait]
+ impl Trait for Unit {
+ async fn method() {
+ let _ = Self;
+ }
+ }
+
+ #[async_trait]
+ impl Trait for Tuple {
+ async fn method() {
+ let _ = Self(0);
+ }
+ }
+
+ #[async_trait]
+ impl Trait for Struct {
+ async fn method() {
+ let _ = Self { x: 0 };
+ }
+ }
+
+ #[async_trait]
+ impl Trait for std::marker::PhantomData<Struct> {
+ async fn method() {
+ let _ = Self;
+ }
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/57
+#[cfg(async_trait_nightly_testing)]
+pub mod issue57 {
+ use crate::executor;
+ use async_trait::async_trait;
+
+ #[async_trait]
+ trait Trait {
+ async fn const_generic<T: Send, const C: usize>(_: [T; C]) {}
+ }
+
+ struct Struct;
+
+ #[async_trait]
+ impl Trait for Struct {
+ async fn const_generic<T: Send, const C: usize>(_: [T; C]) {}
+ }
+
+ #[test]
+ fn test() {
+ let fut = Struct::const_generic([0; 10]);
+ executor::block_on_simple(fut);
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/68
+pub mod issue68 {
+ #[rustversion::since(1.40)] // procedural macros cannot expand to macro definitions in 1.39.
+ #[async_trait::async_trait]
+ pub trait Example {
+ async fn method(&self) {
+ macro_rules! t {
+ () => {{
+ let _: &Self = self;
+ }};
+ }
+ t!();
+ }
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/73
+pub mod issue73 {
+ use async_trait::async_trait;
+
+ #[async_trait]
+ pub trait Example {
+ const ASSOCIATED: &'static str;
+
+ async fn associated(&self) {
+ println!("Associated:{}", Self::ASSOCIATED);
+ }
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/81
+pub mod issue81 {
+ use async_trait::async_trait;
+
+ #[async_trait]
+ pub trait Trait {
+ async fn handle(&self);
+ }
+
+ pub enum Enum {
+ Variant,
+ }
+
+ #[async_trait]
+ impl Trait for Enum {
+ async fn handle(&self) {
+ let Enum::Variant = self;
+ let Self::Variant = self;
+ }
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/83
+pub mod issue83 {
+ use async_trait::async_trait;
+
+ #[async_trait]
+ pub trait Trait {
+ async fn f(&self) {}
+ async fn g(self: &Self) {}
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/85
+pub mod issue85 {
+ #![deny(non_snake_case)]
+
+ use async_trait::async_trait;
+
+ #[async_trait]
+ pub trait Trait {
+ #[allow(non_snake_case)]
+ async fn camelCase();
+ }
+
+ pub struct Struct;
+
+ #[async_trait]
+ impl Trait for Struct {
+ async fn camelCase() {}
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/87
+pub mod issue87 {
+ use async_trait::async_trait;
+
+ #[async_trait]
+ pub trait Trait {
+ async fn f(&self);
+ }
+
+ pub enum Tuple {
+ V(),
+ }
+
+ pub enum Struct {
+ V {},
+ }
+
+ #[async_trait]
+ impl Trait for Tuple {
+ async fn f(&self) {
+ let Tuple::V() = self;
+ let Self::V() = self;
+ let _ = Self::V;
+ let _ = Self::V();
+ }
+ }
+
+ #[async_trait]
+ impl Trait for Struct {
+ async fn f(&self) {
+ let Struct::V {} = self;
+ let Self::V {} = self;
+ let _ = Self::V {};
+ }
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/89
+pub mod issue89 {
+ #![allow(bare_trait_objects)]
+
+ use async_trait::async_trait;
+
+ #[async_trait]
+ trait Trait {
+ async fn f(&self);
+ }
+
+ #[async_trait]
+ impl Trait for Send + Sync {
+ async fn f(&self) {}
+ }
+
+ #[async_trait]
+ impl Trait for dyn Fn(i8) + Send + Sync {
+ async fn f(&self) {}
+ }
+
+ #[async_trait]
+ impl Trait for (dyn Fn(u8) + Send + Sync) {
+ async fn f(&self) {}
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/92
+pub mod issue92 {
+ use async_trait::async_trait;
+
+ macro_rules! mac {
+ ($($tt:tt)*) => {
+ $($tt)*
+ };
+ }
+
+ pub struct Struct<T> {
+ _x: T,
+ }
+
+ impl<T> Struct<T> {
+ const ASSOCIATED1: &'static str = "1";
+ async fn associated1() {}
+ }
+
+ #[async_trait]
+ pub trait Trait
+ where
+ mac!(Self): Send,
+ {
+ const ASSOCIATED2: &'static str;
+ type Associated2;
+
+ #[allow(path_statements, clippy::no_effect)]
+ async fn associated2(&self) {
+ // trait items
+ mac!(let _: Self::Associated2;);
+ mac!(let _: <Self>::Associated2;);
+ mac!(let _: <Self as Trait>::Associated2;);
+ mac!(Self::ASSOCIATED2;);
+ mac!(<Self>::ASSOCIATED2;);
+ mac!(<Self as Trait>::ASSOCIATED2;);
+ mac!(let _ = Self::associated2(self););
+ mac!(let _ = <Self>::associated2(self););
+ mac!(let _ = <Self as Trait>::associated2(self););
+ }
+ }
+
+ #[async_trait]
+ impl<T: Send + Sync> Trait for Struct<T>
+ where
+ mac!(Self): Send,
+ {
+ const ASSOCIATED2: &'static str = "2";
+ type Associated2 = ();
+
+ #[allow(path_statements, clippy::no_effect)]
+ async fn associated2(&self) {
+ // inherent items
+ mac!(Self::ASSOCIATED1;);
+ mac!(<Self>::ASSOCIATED1;);
+ mac!(let _ = Self::associated1(););
+ mac!(let _ = <Self>::associated1(););
+
+ // trait items
+ mac!(let _: <Self as Trait>::Associated2;);
+ mac!(Self::ASSOCIATED2;);
+ mac!(<Self>::ASSOCIATED2;);
+ mac!(<Self as Trait>::ASSOCIATED2;);
+ mac!(let _ = Self::associated2(self););
+ mac!(let _ = <Self>::associated2(self););
+ mac!(let _ = <Self as Trait>::associated2(self););
+ }
+ }
+
+ pub struct Unit;
+
+ #[async_trait]
+ impl Trait for Unit {
+ const ASSOCIATED2: &'static str = "2";
+ type Associated2 = ();
+
+ async fn associated2(&self) {
+ mac!(let Self: Self = *self;);
+ }
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/104
+mod issue104 {
+ use async_trait::async_trait;
+
+ #[async_trait]
+ trait T1 {
+ async fn id(&self) -> i32;
+ }
+
+ macro_rules! impl_t1 {
+ ($ty:ty, $id:expr) => {
+ #[async_trait]
+ impl T1 for $ty {
+ async fn id(&self) -> i32 {
+ $id
+ }
+ }
+ };
+ }
+
+ struct Foo;
+
+ impl_t1!(Foo, 1);
+}
+
+// https://github.com/dtolnay/async-trait/issues/106
+mod issue106 {
+ use async_trait::async_trait;
+ use std::future::Future;
+
+ #[async_trait]
+ pub trait ProcessPool: Send + Sync {
+ type ThreadPool;
+
+ async fn spawn<F, Fut, T>(&self, work: F) -> T
+ where
+ F: FnOnce(&Self::ThreadPool) -> Fut + Send,
+ Fut: Future<Output = T> + 'static;
+ }
+
+ #[async_trait]
+ impl<P: ?Sized> ProcessPool for &P
+ where
+ P: ProcessPool,
+ {
+ type ThreadPool = P::ThreadPool;
+
+ async fn spawn<F, Fut, T>(&self, work: F) -> T
+ where
+ F: FnOnce(&Self::ThreadPool) -> Fut + Send,
+ Fut: Future<Output = T> + 'static,
+ {
+ (**self).spawn(work).await
+ }
+ }
+}
+
+// https://github.com/dtolnay/async-trait/issues/110
+mod issue110 {
+ #![deny(clippy::all)]
+
+ use async_trait::async_trait;
+ use std::marker::PhantomData;
+
+ #[async_trait]
+ pub trait Loader {
+ async fn load(&self, key: &str);
+ }
+
+ pub struct AwsEc2MetadataLoader<'a> {
+ marker: PhantomData<&'a ()>,
+ }
+
+ #[async_trait]
+ impl Loader for AwsEc2MetadataLoader<'_> {
+ async fn load(&self, _key: &str) {}
+ }
+}