src/test/run-pass/union/union-c-interop.rs

   1 // Copyright 2016 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 #![feature(untagged_unions)]
  12
  13 #[derive(Clone, Copy)]
  14 #[repr(C)]
  15 struct LARGE_INTEGER_U {
  16     LowPart: u32,
  17     HighPart: u32,
  18 }
  19
  20 #[derive(Clone, Copy)]
  21 #[repr(C)]
  22 union LARGE_INTEGER {
  23   __unnamed__: LARGE_INTEGER_U,
  24   u: LARGE_INTEGER_U,
  25   QuadPart: u64,
  26 }
  27
  28 #[link(name = "rust_test_helpers")]
  29 extern "C" {
  30     fn increment_all_parts(_: LARGE_INTEGER) -> LARGE_INTEGER;
  31 }
  32
  33 fn main() {
  34     unsafe {
  35         let mut li = LARGE_INTEGER { QuadPart: 0 };
  36         let li_c = increment_all_parts(li);
  37         li.__unnamed__.LowPart += 1;
  38         li.__unnamed__.HighPart += 1;
  39         li.u.LowPart += 1;
  40         li.u.HighPart += 1;
  41         li.QuadPart += 1;
  42         assert_eq!(li.QuadPart, li_c.QuadPart);
  43     }
  44 }