src/libcore/tests/manually_drop.rs

// Copyright 2018 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.

use core::mem::ManuallyDrop;

#[test]
fn smoke() {
    struct TypeWithDrop;
    impl Drop for TypeWithDrop {
        fn drop(&mut self) {
            unreachable!("Should not get dropped");
        }
    }

    let x = ManuallyDrop::new(TypeWithDrop);
    drop(x);

    // also test unsizing
    let x : Box<ManuallyDrop<[TypeWithDrop]>> =
        Box::new(ManuallyDrop::new([TypeWithDrop, TypeWithDrop]));
    drop(x);
}