protected function exprIsQuantifiable($expr)
	{
		$regexps = [
			// A dot or \R
			'(^(?:\\.|\\\\R)$)D',

			// A character class
			'(^\\[\\^?(?:([^\\\\\\]]|\\\\.)(?:-(?-1))?)++\\]$)D'
		];

		return $this->matchesAny($expr, $regexps) || $this->exprIsChar($expr);
	}