Warnings when user object has complex data

So to get down to the nitty gritty, you're proposing changing

elseif ($key != 'roles') {
$out[$key] = $value;
}

to

elseif ($key != 'roles' && is_scalar($value)) {
$out[$key] = $value;
}

That works in some cases. However, I've gone and put an array of objects in my user, so the revised function would look like this (which works):

function mailchimp_mailchimp_merge_values($user) {
$out = array();
$out = (array)$user;
foreach ((array)$user as $key => $value) {
if (is_array($value) && $key != 'role') {
$dup = $value;
foreach ($dup as $key2=>$value2) {
if (!is_scalar($value2)) {
unset($dup,$key2);
}
}
if (is_array(dup) && count($dup) > 0) {
$out[$key] = implode('/', $dup);
} else {
$out[$key] = '';
}
}
elseif (in_array($key, array('login', 'access', 'created'))) {
$out[$key] = date('c', $value);
}
elseif ($key != 'roles' && is_scalar($value)) {
$out[$key] = $value;
}
}

$out = array_merge($out, _mailchimp_get_user_tokens($user));
return $out;
}

It is better than my patch in that it actually works instead of ignoring errors. What do you think about this one?