trait Trait {}

// Make sure casts between thin-pointer <-> fat pointer obey RFC401
fn main() {
    let a: *mut (dyn Trait + 'static) = 0 as *mut _; //~ ERROR casting
    let b: *const str = 0 as *const str; //~ ERROR casting

    let x: *mut (dyn Trait + 'static) = std::ptr::null_mut();
    let y: *const str = std::ptr::null();
    //~^ ERROR the size for values of type `str` cannot be known at compilation time
}