I tried this code:
#![feature(generic_associated_types)]
#![feature(type_alias_impl_trait)]
use std::future::Future;
pub trait Service<Cx, Request> {
type Response;
type Future<'cx>: Future<Output = Self::Response> + Send + 'cx
where
Cx: 'cx,
Self: 'cx;
fn call<'cx, 's>(&'s mut self, cx: &'cx mut Cx, req: Request) -> Self::Future<'cx>
where
's: 'cx;
}
pub struct Test<S>(S);
impl<Cx, Req, S> Service<Cx, Req> for Test<S>
where
Req: Send + 'static,
S: Service<Cx, Req> + Send + 'static,
Cx: Send + 'static,
{
type Response = S::Response;
type Future<'cx> = impl Send + Future<Output = Self::Response> + 'cx
where
Cx: 'cx,
Self: 'cx;
fn call<'cx, 's>(&'s mut self, cx: &'cx mut Cx, req: Req) -> Self::Future<'cx>
where
's: 'cx,
{
async move { self.0.call(cx, req).await }
}
}
fn main() {}
Meta
rustc --version --verbose:
rustc 1.65.0-nightly (d394408fb 2022-08-07)
binary: rustc
commit-hash: d394408fb38c4de61f765a3ed5189d2731a1da91
commit-date: 2022-08-07
host: aarch64-apple-darwin
release: 1.65.0-nightly
LLVM version: 14.0.6
Backtrace
Compiling rust_prove_closure_bug v0.1.0 (/Users/yifei/code/rust_prove_closure_bug)
error[E0478]: lifetime bound not satisfied
--> src/main.rs:28:24
|
28 | type Future<'cx> = impl Send + Future<Output = Self::Response> + 'cx
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: lifetime parameter instantiated with the empty lifetime
note: but lifetime parameter must outlive the lifetime `'cx` as defined here
--> src/main.rs:28:17
|
28 | type Future<'cx> = impl Send + Future<Output = Self::Response> + 'cx
| ^^^
For more information about this error, try `rustc --explain E0478`.
I tried this code:
Meta
rustc --version --verbose:Backtrace