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