src/test/run-pass/issue-2214.rs

   1 // Copyright 2012-2014 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
  12 #![feature(libc)]
  13
  14 extern crate libc;
  15
  16 use std::mem;
  17 use libc::{c_double, c_int};
  18
  19 fn to_c_int(v: &mut isize) -> &mut c_int {
  20     unsafe {
  21         mem::transmute_copy(&v)
  22     }
  23 }
  24
  25 fn lgamma(n: c_double, value: &mut isize) -> c_double {
  26     unsafe {
  27         return m::lgamma(n, to_c_int(value));
  28     }
  29 }
  30
  31 mod m {
  32     use libc::{c_double, c_int};
  33
  34     #[link_name = "m"]
  35     extern {
  36         #[cfg(unix)]
  37         #[link_name="lgamma_r"]
  38         pub fn lgamma(n: c_double, sign: &mut c_int) -> c_double;
  39         #[cfg(windows)]
  40         #[link_name="lgamma"]
  41         pub fn lgamma(n: c_double, sign: &mut c_int) -> c_double;
  42     }
  43 }
  44
  45 pub fn main() {
  46   let mut y: isize = 5;
  47   let x: &mut isize = &mut y;
  48   assert_eq!(lgamma(1.0 as c_double, x), 0.0 as c_double);
  49 }