os-rust/src/test/run-pass/packed/packed-struct-borrow-element.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.

// run-pass
// ignore-emscripten weird assertion?

#![feature(repr_packed)]

#[repr(packed)]
struct Foo1 {
    bar: u8,
    baz: usize
}

#[repr(packed(2))]
struct Foo2 {
    bar: u8,
    baz: usize
}

#[repr(C, packed(4))]
struct Foo4C {
    bar: u8,
    baz: usize
}

pub fn main() {
    let foo = Foo1 { bar: 1, baz: 2 };
    let brw = unsafe { &foo.baz };
    assert_eq!(*brw, 2);

    let foo = Foo2 { bar: 1, baz: 2 };
    let brw = unsafe { &foo.baz };
    assert_eq!(*brw, 2);

    let foo = Foo4C { bar: 1, baz: 2 };
    let brw = unsafe { &foo.baz };
    assert_eq!(*brw, 2);
}