"Das war zu einfach" - Sorin

easy_things.php

<?php

declare(strict_types=1);

function assertConstantOfClass(string $class, $constantValue): void
{
    $reflection = new ReflectionClass($class);
    $constants = $reflection->getConstants();
    foreach ($constants as $value) {
        if ($value === $constantValue) {
            return;
        }
    }
    throw new Exception(sprintf('The value "%s" is not defined as a constant of class "%s"', $constantValue, $class));
}

echo '----------------------- ENUMS';


abstract class Enum
{
    /** @var mixed */
    private $value;

    /** @param mixed $value */
    final private function __construct($value)
    {
        $this->value = $value;
    }

    final public static function __callStatic($name, $arguments)
    {
        $constant = 'static::' . $name;
        if (defined($constant)) {
            return new static(constant($constant));
        }
        throw new LogicException(sprintf('The enum "%s" does not contain "%s"', static::class, $name));
    }
}

/**
 * @method MyEnum FOO()
 * @method MyEnum BAR()
 */
final class MyEnum extends Enum
{
    protected const FOO = 'FOO';
    protected const BAR = 'BAR';
}

/**
 * @method YourEnum FOO()
 * @method YourEnum BAR()
 */
final class YourEnum extends Enum
{
    protected const FOO = 'FOO';
    protected const BAR = 'BAR';
}

function compareFunc(Enum $type): bool
{
    return $type == MyEnum::FOO();
}

var_dump(compareFunc(MyEnum::FOO()));
var_dump(compareFunc(MyEnum::BAR()));
var_dump(compareFunc(YourEnum::FOO()));
var_dump(compareFunc(YourEnum::BAR()));