}
</pre>

<h4 id="General_interfaces">General interfaces</h4>

<p>
In their most general form, an interface element may also be an arbitrary type term
<code>T</code>, or a term of the form <code>~T</code> specifying the underlying type <code>T</code>,
or a union of terms <code>t<sub>1</sub>|t<sub>2</sub>|…|t<sub>n</sub></code>
[<a href="#Go_1.18">Go 1.18</a>].

* Raise an exception when using form data (`Form`, `File`) without having `python-multipart` installed.
    * Up to now the application would run, and raise an exception only when receiving a request with form data, the new behavior, raising early, will prevent from deploying applications with broken dependencies.