src/test/ui/coercion/coerce-to-bang-cast.rs

fn foo(x: usize, y: !, z: usize) { }

fn cast_a() {
    let y = {return; 22} as !;
    //~^ ERROR non-primitive cast
}

fn cast_b() {
    let y = 22 as !; //~ ERROR non-primitive cast
}

fn main() { }