| // Regression test for #20831: debruijn index account was thrown off |
| // by the (anonymous) lifetime in `<Self as Publisher>::Output` |
| // below. Note that changing to a named lifetime made the problem go |
| // away. |
| |
| use std::cell::RefCell; |
| use std::ops::{Shl, Shr}; |
| |
| pub trait Subscriber { |
| type Input; |
| } |
| |
| pub trait Publisher<'a> { |
| type Output; |
| fn subscribe(&mut self, _: Box<dyn Subscriber<Input=Self::Output> + 'a>); |
| } |
| |
| pub trait Processor<'a> : Subscriber + Publisher<'a> { } |
| |
| impl<'a, P> Processor<'a> for P where P : Subscriber + Publisher<'a> { } |
| |
| struct MyStruct<'a> { |
| sub: Box<dyn Subscriber<Input=u64> + 'a> |
| } |
| |
| impl<'a> Publisher<'a> for MyStruct<'a> { |
| type Output = u64; |
| fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) { |
| // Not obvious, but there is an implicit lifetime here -------^ |
| //~^^ ERROR cannot infer |
| //~| ERROR cannot infer |
| //~| ERROR mismatched types |
| //~| ERROR mismatched types |
| // |
| // The fact that `Publisher` is using an implicit lifetime is |
| // what was causing the debruijn accounting to be off, so |
| // leave it that way! |
| self.sub = t; |
| } |
| } |
| |
| fn main() {} |
