src/test/run-pass/issues/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 // run-pass
  12 // ignore-wasm32-bare no libc to test ffi with
  13
  14 #![feature(libc)]
  15
  16 extern crate libc;
  17
  18 use std::mem;
  19 use libc::{c_double, c_int};
  20
  21 fn to_c_int(v: &mut isize) -> &mut c_int {
  22     unsafe {
  23         mem::transmute_copy(&v)
  24     }
  25 }
  26
  27 fn lgamma(n: c_double, value: &mut isize) -> c_double {
  28     unsafe {
  29         return m::lgamma(n, to_c_int(value));
  30     }
  31 }
  32
  33 mod m {
  34     use libc::{c_double, c_int};
  35
  36     #[link_name = "m"]
  37     extern {
  38         #[cfg(any(unix, target_os = "cloudabi"))]
  39         #[link_name="lgamma_r"]
  40         pub fn lgamma(n: c_double, sign: &mut c_int) -> c_double;
  41         #[cfg(windows)]
  42         #[link_name="lgamma"]
  43         pub fn lgamma(n: c_double, sign: &mut c_int) -> c_double;
  44     }
  45 }
  46
  47 pub fn main() {
  48   let mut y: isize = 5;
  49   let x: &mut isize = &mut y;
  50   assert_eq!(lgamma(1.0 as c_double, x), 0.0 as c_double);
  51 }