rust/tests/run-pass/intrinsics.rs

#![feature(core_intrinsics)]

use std::intrinsics;
use std::mem::{size_of, size_of_val};

struct Bomb;

impl Drop for Bomb {
    fn drop(&mut self) {
        eprintln!("BOOM!");
    }
}

fn main() {
    assert_eq!(size_of::<Option<i32>>(), 8);
    assert_eq!(size_of_val(&()), 0);
    assert_eq!(size_of_val(&42), 4);
    assert_eq!(size_of_val(&[] as &[i32]), 0);
    assert_eq!(size_of_val(&[1, 2, 3] as &[i32]), 12);
    assert_eq!(size_of_val("foobar"), 6);

    assert_eq!(intrinsics::type_name::<Option<i32>>(), "core::option::Option<i32>");

    assert_eq!(intrinsics::likely(false), false);
    assert_eq!(intrinsics::unlikely(true), true);

    unsafe { intrinsics::forget(Bomb); }
}