title: *ngIf with compound conditionals performance
body: <p>It is known that calling a function in a *ngIf may be bad for performance, as it will be evaluated in every change detection cycle. Instead, it is recommended the use of primitive (number, boolean,..) or immutable values.</p>
  
  <p>My question is if compound conditionals in a *ngIf are treated in the same way. I guess that it is also executed in each change detection, but I would like to confirm it.</p>
  
  <p>For example:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;div *ngFor="let item of items; trackBy: itemById"&gt;
      &lt;button *ngIf="item.showAction &amp;&amp; otherComponentCondition"&gt;Next&lt;/button&gt;
  &lt;/div&gt;
  </code></pre>