Asssociated type declared in where clause is not enforced in type parameter #116864
Description
For some reason FnMutFut<&'any BAZ::Param, ()> is not being inferred as FnMutFut<&'any i32, ()>, which results in an unsatisfied trait bound error.
use std::future::Future; pub trait Baz { type Param; } pub trait FnMutFut<P, R>: FnMut(P) -> Self::Future { type Future: Future<Output = R>; } impl<P, F, FUT, R> FnMutFut<P, R> for F where F: FnMut(P) -> FUT, FUT: Future<Output = R>, { type Future = FUT; } pub async fn does_not_work<BAZ>(_: BAZ, mut cb: impl for<'any> FnMutFut<&'any BAZ::Param, ()>) where BAZ: Baz<Param = i32>, { cb(&1i32).await; }Perhaps something involving the generic implementation of FnMutFut? Perhaps something involving impl trait?