src/test/ui/never_type/dispatch_from_dyn_zst.rs

   1 // run-pass
   2
   3 #![feature(unsize, dispatch_from_dyn, never_type)]
   4
   5 #![allow(dead_code)]
   6
   7 use std::{
   8     ops::DispatchFromDyn,
   9     marker::{Unsize, PhantomData},
  10 };
  11
  12 struct Zst;
  13 struct NestedZst(PhantomData<()>, Zst);
  14
  15
  16 struct WithUnit<T: ?Sized>(Box<T>, ());
  17 impl<T: ?Sized, U: ?Sized> DispatchFromDyn<WithUnit<U>> for WithUnit<T>
  18     where T: Unsize<U> {}
  19
  20 struct WithPhantom<T: ?Sized>(Box<T>, PhantomData<()>);
  21 impl<T: ?Sized, U: ?Sized> DispatchFromDyn<WithPhantom<U>> for WithPhantom<T>
  22     where T: Unsize<U> {}
  23
  24 struct WithNever<T: ?Sized>(Box<T>, !);
  25 impl<T: ?Sized, U: ?Sized> DispatchFromDyn<WithNever<U>> for WithNever<T>
  26     where T: Unsize<U> {}
  27
  28 struct WithZst<T: ?Sized>(Box<T>, Zst);
  29 impl<T: ?Sized, U: ?Sized> DispatchFromDyn<WithZst<U>> for WithZst<T>
  30     where T: Unsize<U> {}
  31
  32 struct WithNestedZst<T: ?Sized>(Box<T>, NestedZst);
  33 impl<T: ?Sized, U: ?Sized> DispatchFromDyn<WithNestedZst<U>> for WithNestedZst<T>
  34     where T: Unsize<U> {}
  35
  36
  37 struct Generic<T: ?Sized, A>(Box<T>, A);
  38 impl<T: ?Sized, U: ?Sized> DispatchFromDyn<Generic<U, ()>> for Generic<T, ()>
  39     where T: Unsize<U> {}
  40 impl<T: ?Sized, U: ?Sized> DispatchFromDyn<Generic<U, PhantomData<()>>>
  41     for Generic<T, PhantomData<()>>
  42     where T: Unsize<U> {}
  43 impl<T: ?Sized, U: ?Sized> DispatchFromDyn<Generic<U, !>> for Generic<T, !>
  44     where T: Unsize<U> {}
  45 impl<T: ?Sized, U: ?Sized> DispatchFromDyn<Generic<U, Zst>> for Generic<T, Zst>
  46     where T: Unsize<U> {}
  47 impl<T: ?Sized, U: ?Sized> DispatchFromDyn<Generic<U, NestedZst>> for Generic<T, NestedZst>
  48     where T: Unsize<U> {}
  49
  50
  51 fn main() {}