<pre>
type ReadCloser interface {
	Reader   // includes methods of Reader in ReadCloser's method set
	Close()  // illegal: signatures of Reader.Close and Close are different
}
</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>,