&gt; But it doesn&#x27;t support switching the semantics of safe code to unsafe with a build flag<p>Jai allow this for array indexing AND it also allow the reverse: reinserting array checks even when there is an &#x27;unsafe access&#x27; operation: this way even if you made a mistake in adding an &#x27;unsafe access&#x27; operation it&#x27;s easy to find where the error is (assuming the error is reproducible of course).