src/test/run-pass/issues/issue-41677.rs

   1 // Copyright 2016 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // run-pass
  12 // Regression test for #41677. The local variable was winding up with
  13 // a type `Receiver<?T, H>` where `?T` was unconstrained, because we
  14 // failed to enforce the WF obligations and `?T` is a bivariant type
  15 // parameter position.
  16
  17 #![allow(unused_variables, dead_code)]
  18
  19 use std::marker::PhantomData;
  20
  21 trait Handle {
  22     type Inner;
  23 }
  24
  25 struct ResizingHandle<H>(PhantomData<H>);
  26 impl<H> Handle for ResizingHandle<H> {
  27     type Inner = H;
  28 }
  29
  30 struct Receiver<T, H: Handle<Inner=T>>(PhantomData<H>);
  31
  32 fn channel<T>(size: usize) -> Receiver<T, ResizingHandle<T>> {
  33     let rx = Receiver(PhantomData);
  34     rx
  35 }
  36
  37 fn main() {
  38 }