#[repr(C)]
struct VB { _data: [u8; 0] }

#[link(name = "vb")]
extern "C" {
    #[link_name = "vbInit"]
    fn vb_init(sim: *mut VB) -> *mut VB;

    #[link_name = "vbSizeOf"]
    fn vb_size_of() -> usize;

    #[link_name = "vbGetKeys"]
    fn vb_get_keys(sim: *mut VB) -> u16;
}

pub struct CoreVB {
    sim: *mut VB,
    _data: Box<[u8]>,
}

impl CoreVB {
    pub fn new() -> Self {
        let size = unsafe { vb_size_of() };
        let mut data = vec![0; size].into_boxed_slice();
        let sim = data.as_mut_ptr() as *mut VB;
        unsafe { vb_init(sim) };
        CoreVB {
            sim,
            _data: data
        }
    }

    pub fn keys(&self) -> u16 {
        unsafe { vb_get_keys(self.sim) }
    }
}