72 lines
1.2 KiB
Rust
72 lines
1.2 KiB
Rust
// build-pass
|
|
// edition:2018
|
|
|
|
type BoxFuture<T> = std::pin::Pin<Box<dyn std::future::Future<Output=T>>>;
|
|
|
|
fn main() {
|
|
f();
|
|
}
|
|
|
|
async fn f() {
|
|
run("dependency").await;
|
|
}
|
|
|
|
struct InMemoryStorage;
|
|
|
|
struct User<'dep> {
|
|
dep: &'dep str,
|
|
}
|
|
|
|
impl<'a> StorageRequest<InMemoryStorage> for SaveUser<'a> {
|
|
fn execute(&self) -> BoxFuture<Result<(), String>> {
|
|
todo!()
|
|
}
|
|
}
|
|
|
|
trait Storage {
|
|
type Error;
|
|
}
|
|
|
|
impl Storage for InMemoryStorage {
|
|
type Error = String;
|
|
}
|
|
|
|
trait StorageRequestReturnType {
|
|
type Output;
|
|
}
|
|
|
|
trait StorageRequest<S: Storage>: StorageRequestReturnType {
|
|
fn execute(
|
|
&self,
|
|
) -> BoxFuture<Result<<Self as StorageRequestReturnType>::Output, <S as Storage>::Error>>;
|
|
}
|
|
|
|
struct SaveUser<'a> {
|
|
name: &'a str,
|
|
}
|
|
|
|
impl<'a> StorageRequestReturnType for SaveUser<'a> {
|
|
type Output = ();
|
|
}
|
|
|
|
impl<'dep> User<'dep> {
|
|
async fn save<S>(self)
|
|
where
|
|
S: Storage,
|
|
for<'a> SaveUser<'a>: StorageRequest<S>,
|
|
{
|
|
SaveUser { name: "Joe" }
|
|
.execute()
|
|
.await;
|
|
}
|
|
}
|
|
|
|
async fn run<S>(dep: &str)
|
|
where
|
|
S: Storage,
|
|
for<'a> SaveUser<'a>: StorageRequest<S>,
|
|
for<'a> SaveUser<'a>: StorageRequestReturnType,
|
|
{
|
|
User { dep }.save().await;
|
|
}
|