Enum1.php

enum Option {
  case None = new class {};

  case Some = new class($val) {
      public function __construct(private $val) {}
      public function value() { return $val; }
  };

  public function value{} { throw new TypeError; }
}

Enum2.php

enum Option {
  case None;

  case Some = new Some($val);

  public function value{} { throw new TypeError; }
}

class Some extends Option {
    public function __construct(private $val) {}
    public function value() { return $val; }
};