main.rs

#![feature(lang_items, start)]
#![no_std]

#[link(name = "c")]
extern {
  fn puts(s: *const u8) -> isize;
  fn abort() -> !;
}

#[lang = "panic_fmt"]
#[no_mangle]
pub extern fn panic_fmt() -> ! { unsafe { abort() } }

#[lang = "eh_personality"]
#[no_mangle]
pub extern fn eh_personality() {}

#[lang = "eh_unwind_resume"]
#[no_mangle]
pub extern fn eh_unwind_resume() {}

struct MyType {
  integer: i32
}

impl MyType {
  pub fn new(flag: bool) -> Result<MyType, ()> {
    if flag { Ok(MyType { integer: 5 }) } else { Err(()) }
  }
}

#[start]
fn main(_argc: isize, _argv: *const *const u8) -> isize {
  unsafe { puts(b"Hello, world\0" as *const u8); }
  let s = MyType::new(true).unwrap();
  0
}