tests/ui/type-alias-impl-trait/issue-63279.rs

#![feature(type_alias_impl_trait)]

type Closure = impl FnOnce();

#[define_opaque(Closure)]
fn c() -> Closure {
    //~^ ERROR: expected an `FnOnce()` closure, found `()`
    || -> Closure { || () }
    //~^ ERROR: mismatched types
    //~| ERROR: mismatched types
    //~| ERROR: expected an `FnOnce()` closure, found `()`
}

fn main() {}