<code>len(src)</code> and <code>len(dst)</code>.
As a special case, <code>copy</code> also accepts a destination argument assignable
to type <code>[]byte</code> with a source argument of a string type.
This form copies the bytes from the string into the byte slice.
</p>

<pre class="grammar">
copy(dst, src []T) int
copy(dst []byte, src string) int
</pre>

<p>
Examples:
</p>

<pre>