&gt; Specifically, now every caller to this function has to pass in a mode value, even if the file exists, even if they don’t really care and are happy with a default file mode.<p>Wouldn&#x27;t this be solved by allowing for optional arguments (which go doesn&#x27;t seem to support)? Also, why not just _explicitly_ set the file mode, even if the file still exists (as otherwise it would fail anyways)?