S = struct
{
    a: u32,
    b: u32,
    c: u64,
    d: u64,
    e: u64
}

require = fn (ok: u1) void
{
    if (!ok)
    {
        #trap();
    }
}

va_arg_fn = fn [cc(c)] (first_arg: u32, ...) void
{
    if (first_arg != 123456789)
    {
        #trap();
    }

    >va = #va_start();

    >s = #va_arg(&va, S);
    require(s.a == 5);
    require(s.b == 4);
    require(s.c == 3);
    require(s.d == 2);
    require(s.e == 1);
}

[export] main = fn [cc(c)] () s32
{
    >first_arg: u32 = 123456789;
    >s : S = {
        .a = 5,
        .b = 4,
        .c = 3,
        .d = 2,
        .e = 1,
    };
    va_arg_fn(first_arg, s);
    return 0;
}