#![allow(unused_variables)]
fn main() {
    use std::ffi::{CString, CStr};
    let c_string = CString::from(c"foo");
    let cstr = c_string.as_c_str();
    assert_eq!(
        cstr, CStr::from_bytes_with_nul(b"foo\0")
        .expect("CStr::from_bytes_with_nul failed")
    );
}