="Sh" id="RETURN_VALUES"><a class="selflink" href="#RETURN_VALUES">RETURN
  VALUES</a></h1>
<b class="Fn" title="Fn">crypto_x25519</b>() and
  <b class="Fn" title="Fn">crypto_x25519_public_key</b>() return nothing.
<h1 class="Sh" title="Sh" id="EXAMPLES"><a class="selflink" href="#EXAMPLES">EXAMPLES</a></h1>
The following example assumes the existence of
  <b class="Fn" title="Fn">arc4random_buf</b>(), which fills the given buffer
  with cryptographically secure random bytes. If
  <b class="Fn" title="Fn">a