WordPress at a glance
function is not described

get_available_post_statuses() WP 2.5.0

Get all the possible statuses for a post_type

No Hooks.

Return

Array. As array of all the statuses for the supplied post type

Usage

get_available_post_statuses( $type );
$type(string)
The post_type you want the statuses for
Default: 'post'

Code of get available post statuses: wp-admin/includes/post.php WP 5.2.1

<?php
function get_available_post_statuses( $type = 'post' ) {
	$stati = wp_count_posts( $type );

	return array_keys( get_object_vars( $stati ) );
}