#![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::>(), 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::>(), "core::option::Option"); assert_eq!(intrinsics::likely(false), false); assert_eq!(intrinsics::unlikely(true), true); unsafe { intrinsics::forget(Bomb); } }