global $current_user;
echo $current_user->roles[0];

/**
 * Determines if the specified post is an autosave.
 *
 * @since 2.6.0
 *
 * @param int|object $post Post ID or post object.
 * @return bool|int False if not a revision, ID of autosave's parent otherwise
 */
function wp_is_post_autosave( $post ) {

function wpse_save_post_meta( $post_id ) {

    // verify nonce
    if (!isset($_POST['cpt_wpse_nonce']) || !wp_verify_nonce($_POST['cpt_wpse_nonce'], basename(__FILE__)))
        return $post_id;
    // check autosave
    if ( defined('DOING_AUTOSAVE') && DOING_AUTOSAVE )
        return $post_id;
    // check permissions
    if ( 'wpse' == $_POST['post_type'] ) {
        if ( !current_user_can('edit_page', $post_id) )
            return $post_id;
        } elseif ( !current_user_can('edit_post', $post_id) ) {

public function save( $post_id, \WP_Post $post ) {

	$status = $this->validator->status( $post );

	if ( Post_Validator::OK !== $status )
		return $status;

	// save the data
}

public function save( $post_id, \WP_Post $post) {

    try {

       // throws an exception if bad status or any other reason
       $this->validator->validate( $post );

       // save data here

    } catch( \Exception $e ) {

        return new \WP_Error( $e->getCode(), $e->getMessage(), $e->getTrace() );
    }
}