global $scoper;

$reqd_caps = array( 'edit_published_posts', 'edit_others_posts' );
$cols = COL_ID_RS;  // will return 1D array of user IDs.  For 2D array of all user cols, pass COLS_ALL_RS
$data_source_name = 'post';  // use this for posts or pages
$object_id = 0;  // set to nonzero to return users for a specific post

$users = $scoper->users_who_can($reqd_caps, $cols, $data_source_name, $object_id );