src/test/ui/const-generics/generic_const_exprs/issue-85848.rs

   1 #![feature(generic_const_exprs)]
   2 #![allow(incomplete_features)]
   3
   4 trait _Contains<T> {
   5     const does_contain: bool;
   6 }
   7
   8 trait Contains<T, const Satisfied: bool> {}
   9
  10 trait Delegates<T> {}
  11
  12 impl<T, U> Delegates<U> for T where T: Contains<U, true> {}
  13
  14 const fn contains<A, B>() -> bool
  15 where
  16     A: _Contains<B>,
  17 {
  18     A::does_contain
  19 }
  20
  21 impl<T, U> Contains<T, { contains::<T, U>() }> for U where T: _Contains<U> {}
  22
  23 fn writes_to_path<C>(cap: &C) {
  24     writes_to_specific_path(&cap);
  25     //~^ ERROR: the trait bound `(): _Contains<&C>` is not satisfied [E0277]
  26     //~| ERROR: unconstrained generic constant
  27     //~| ERROR: mismatched types [E0308]
  28 }
  29
  30 fn writes_to_specific_path<C: Delegates<()>>(cap: &C) {}
  31
  32 fn main() {}