tests/ui/traits/negative-bounds/opaque-type-unsatisfied-fn-bound.rs

// compile-flags: -Znext-solver

#![feature(negative_bounds, unboxed_closures)]

fn produce() -> impl !Fn<(u32,)> {}
//~^ ERROR type mismatch resolving `() == impl !Fn<(u32,)>`

fn main() {}