ToConfig.php

<?php

declare (strict_types=1);
namespace Drupal\Core\Form;


/**
 * Enumeration of the special return values for ConfigTarget toConfig callables.
 *
 * @see \Drupal\Core\Form\ConfigTarget
 */
enum ToConfig
{
    // Appropriate to return from a toConfig callable when another toConfig
    // callable handles setting this property path. In other words: "no-op".
    case NoOp;
    // Appropriate to return from a toConfig callable when the given form value
    // should result in the targeted property path getting deleted.
    // @see \Drupal\Core\Config\Config::clear()
    case DeleteKey;
}