 becomes type u3 = A of int | Default_v of int * double
</pre><p>
All IDL unions must be discriminated, either via the special syntax
<span class=machine><span class=font-tt>union </span></span><span class=font-it>name</span><span class=machine><span class=font-tt> switch(int </span></span><span class=font-it>discr</span><span class=machine><span class=font-tt>)</span></span>…, or via the
attribute <span class=machine><span class=font-tt>switch</span></span><span class=machine><span class=font-tt>_</span>