Rust FFI

Build log

   Compiling sample v0.1.0 (file:///tmp/sample)
main.rs:11:23: 11:26 error: cannot borrow immutable local variable `str` as mutable
main.rs:11     unsafe { foo(&mut str) };
                                 ^~~
error: aborting due to previous error
Could not compile `sample`.

To learn more, run the command again with --verbose.

main.rs

use std::os::raw::c_char;
use std::ptr::{null_mut};

#[link(name="sample")]
extern {
    fn foo(_: *mut *mut c_char);
}

fn main() {
    let str: *mut c_char = null_mut();
    unsafe { foo(&mut str) };
    // ...
}

sample.h

#ifndef _SAMPLE_H
#define _SAMPLE_H

void foo(char **pbuf);

#endif /* _SAMPLE_H */