type <code>S</code> and returns the resulting slice, also of type
<code>S</code>.
The values <code>x</code> are passed to a parameter of type <code>...E</code>
where <code>E</code> is the element type of <code>S</code>
and the respective <a href="#Passing_arguments_to_..._parameters">parameter
passing rules</a> apply.
As a special case, <code>append</code> also accepts a slice whose type is assignable to