function string_array(fallback) {
	return validate(fallback, (input, keypath) => {
		if (!Array.isArray(input) || input.some((value) => typeof value !== 'string')) {
			throw new Error(`${keypath} must be an array of strings, if specified`);
		}

		return input;
	});
}
@param {string[] | undefined} [fallback]
@returns {Validator}