Yes.

My theme’s functions.php file has this:

add_action('init', 'my_init_function');
function my_init_function(){
  if(is_admin()){
   include_once('class-piklist-checker.php');
 
   if (!piklist_checker::check(__FILE__, 'theme')){ //use 'theme' parameter when included in a theme
     return;
   }
  }
}

function piklist_event_post_types($post_types)
  {
	$post_types['event'] = array(
	  'labels' => piklist('post_type_labels', 'Event')
	  ,'title' => __('Enter a new Event Title')
	  ,'menu_icon' => piklist('url', 'piklist') . '/parts/img/piklist-menu-icon.svg'
	  ,'page_icon' => piklist('url', 'piklist') . '/parts/img/piklist-page-icon-32.png'
	  ,'supports' => array(
		'title'
		,'post-formats'
	  )
	  ,'public' => true
	  ,'admin_body_class' => array(
		'custom-body-class'
	  )
	  ,'has_archive' => true
	  ,'rewrite' => array(
		'slug' => 'event'
	  )
	  ,'capability_type' => 'post'
	  ,'edit_columns' => array(
		'title' => __('Event')
		,'author' => __('Assigned to')
	  )
	  ,'hide_meta_box' => array(
		'author'
	  )
	  ,'status' => array(
		'new' => array(
		  'label' => 'New'
		  ,'public' => false
		)
		,'pending' => array(
		  'label' => 'Pending Review'
		  ,'public' => false
		)
		,'event' => array(
		  'label' => 'Event'
		  ,'public' => true
		  ,'exclude_from_search' => true
		  ,'show_in_admin_all_list' => true
		  ,'show_in_admin_status_list' => true
	   )
		,'lock' => array(
		  'label' => 'Lock'
		  ,'public' => true
		)
	  )
	);
	return $post_types;

And my meta box has this:

piklist('field',array(
    'name' => 'email',
    'type' => 'text',
    'label' => 'E-mail',
    'validate' => array(
          array(
               'type' => 'email'
          )
     )
));