Memory tests

gistfile1.txt

extern crate libc;

use libc::c_void;
use std::ops::Drop;
use std::intrinsics::forget;
use std::ptr::swap;

struct Foo { x: int }

impl Drop for Foo {
  fn drop(&mut self) {
    println!("We discarded our foo thanks!");
  }
}

fn main() {
  let mut x = ~Foo { x: 10 };

  let mut y = & mut *x as * mut Foo;
  println!("Address Y: {:x}", y as uint);

  let mut z = y as * mut c_void;
  println!("Address Z: {:x}", z as uint);

  // Forget x so we don't worry about it
  unsafe { forget(x); }

  {
    let res_x:~Foo;
    unsafe {
      let mut res_z = z as * mut Foo;
      println!("Ressurected Z: {:x}", z as uint);

      let mut res_y = & mut (*res_z);
      println!("Ressurected Y: {:x}", y as uint);

      let mut tmp = ~Foo { x: 10 };
      let tp = & mut *tmp as * mut Foo;
      swap(res_y, tp);
      res_x = tmp;
      println!("Temp variable should end here");
    }
    println!("Outside space");
  }
}