foo = macro [T] (ptr: &u32) &T
{
    return #pointer_cast(ptr);
}

A = struct
{
    a: u32,
}

B = struct
{
    b: u32,
}

[export] main = fn [cc(c)] () s32
{
    >var: u32 = 0;
    >a = foo[A](&var);
    >b = foo[B](&var);
    a.a = 1;
    if (b.b != 1) #trap();
    if (var != 1) #trap();
    return 0;
}