">data</span> <span class="dt">real</span> x) {</span>
<span id="cb9-2"><a href="#cb9-2" aria-hidden="true" tabindex="-1"></a>  <span class="cf">return</span> x^<span class="dv">2</span>;</span>
<span id="cb9-3"><a href="#cb9-3" aria-hidden="true" tabindex="-1"></a>}</span></code><button title="Copy to Clipboard" class="code-copy-button"><i class="bi"></i></button></pre></div>
<p>requires the argument <code>x</code> to be data only.</p>
<p>Declaring an argument data only allows type inference to proceed in 