classes/Errors/ErrorHandlerManager.php
protected function matchesTypehint($handler, Exception $exception)
	{
		if ($handler instanceof ErrorHandlerInterface) {
			return true;
		}

		if (is_array($handler)) {
			$reflection = (new ReflectionMethod($handler[0], $handler[1]));
		} else {
			$reflection = (new ReflectionFunction($handler));
		}

		$params = $reflection->getParameters();

		// if the handler takes no parameters it is considered global and should
		// handle every exception
		if (empty($params)) {
			return true;
		}

		$handlerHint = $params[0]
			->getClass();

		// likewise, if the first handler parameter has no typehint, consider it
		// a global handler that handles everything
		if (!$handlerHint) {
			return true;
		}

		return $handlerHint->isInstance($exception);
	}
protected function matchesTypehint($handler, Exception $exception)
	{
		if ($handler instanceof ErrorHandlerInterface) {
			return true;
		}

		if (is_array($handler)) {
			$reflection = (new ReflectionMethod($handler[0], $handler[1]));
		} else {
			$reflection = (new ReflectionFunction($handler));
		}

		$params = $reflection->getParameters();

		// if the handler takes no parameters it is considered global and should
		// handle every exception
		if (empty($params)) {
			return true;
		}

		$handlerHint = $params[0]
			->getClass();

		// likewise, if the first handler parameter has no typehint, consider it
		// a global handler that handles everything
		if (!$handlerHint) {
			return true;
		}

		return $handlerHint->isInstance($exception);
	}
Check if a handler's argument typehint matches an exception.

@param  callable|ErrorHandlerInterface $handler
@param  \Exception                     $exception

@return bool