test.rs

#![feature(lang_items)]
#![allow(unstable)]
#![allow(non_camel_case_types)]

extern crate libc;
extern crate unicode;

mod w32 {
	use libc::types::os::arch::extra::{HANDLE, LPCWSTR};

	pub type UINT = u32;
	pub type INT = i32;
	pub type HWND = HANDLE;
	pub type LPCTSTR = LPCWSTR;

	#[link(name = "user32")]
	extern "stdcall" {
		pub fn MessageBoxW(hWnd: HWND, lpText: LPCTSTR, lpCaption: LPCTSTR, uType: UINT) -> INT;
	}
}

macro_rules! L(
	($e: expr) => ({
		((|&: s: &str| -> Vec<u16> {
			let mut v: Vec<u16> = s.utf16_units().collect();
			v.push(0);
			return v;
		})($e)).as_ptr()
	})
);

fn main() {
	unsafe {
		w32::MessageBoxW(std::ptr::null_mut(), L!("Yodélilà"), L!("YO YO YO YO"), 0);
	}
}