name : CarbonPeriodImmutable.php <?php declare(strict_types=1); /** * This file is part of the Carbon package. * * (c) Brian Nesbitt <brian@nesbot.com> * * For the full copyright and license information, please view the LICENSE * file that was distributed with this source code. */ namespace Carbon; class CarbonPeriodImmutable extends CarbonPeriod { /** * Default date class of iteration items. * * @var string */ protected const DEFAULT_DATE_CLASS = CarbonImmutable::class; /** * Date class of iteration items. */ protected string $dateClass = CarbonImmutable::class; /** * Prepare the instance to be set (self if mutable to be mutated, * copy if immutable to generate a new instance). */ protected function copyIfImmutable(): static { return $this->constructed ? clone $this : $this; } }