Enum

BaseEnum.php

<?php

declare(strict_types=1);

namespace App\Common\Enum;

use ReflectionException;
use ReflectionClass;
use InvalidArgumentException;

abstract class BaseEnum
{
    protected $value;

    /**
     * BaseEnum constructor.
     * @param $value
     * @throws ReflectionException
     */
    final public function __construct($value)
    {
        $c = new ReflectionClass($this);
        if (!in_array($value, $c->getConstants())) {
            throw new InvalidArgumentException("Invalid enum value");
        }
        $this->value = $value;
    }

    /**
     * @return mixed
     */
    final public function __toString()
    {
        return $this->value;
    }
}

demo.php

<?php

$example = new EntityTypeEnum(EntityTypeEnum::INVESTOR);

EntityTypeEnum.php

<?php

namespace App\Common\Enum;

class EntityTypeEnum extends BaseEnum
{
    // entity type mapping is shared between projects
    const INVESTOR = 0;
    const FUND = 1;
    const MANAGER = 2;
    const CONSULTANT = 3;
    const MANDATE = 4;
    const INVESTMENT = 5;
}