p">&gt;</span> <span class="ident">TokenStream</span> {
    <span class="macro">unimplemented</span><span class="macro">!</span>()
}</pre></div>
<p>If, for some reason, you can't place it like that you can use
<code>#[proc_macro_error(proc_macro_hack)]</code> instead.</p>
<h1 id="note" class="section-header"><a href="#note">Note</a></h1>
<p>If <code>proc-macro-hack</code> was detected (by any means) <code>allow_not_macro</code>
and <code>assert_unwind_safe</code> will be applied automatically.</p>
</li>
<li