rust/src/test/run-pass/issue-4735.rs

// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

// ignore-fast doesn't like extern crate

extern crate libc;

use std::cast::transmute;
use libc::c_void;

struct NonCopyable(*c_void);

impl Drop for NonCopyable {
    fn drop(&mut self) {
        let NonCopyable(p) = *self;
        let _v = unsafe { transmute::<*c_void, Box<int>>(p) };
    }
}

pub fn main() {
    let t = box 0;
    let p = unsafe { transmute::<Box<int>, *c_void>(t) };
    let _z = NonCopyable(p);
}