In Koire v. Metro Car Wash (1985) 40 Cal.3d 24, a case involving allegations of discrimination on the basis of sex--a statutory classification--the Supreme Court both explained and applied the "arbitrari-ness" rule, concluding that while some gender-based distinctions would be permissible (separate restrooms), others would not ("Ladies' Day" discounts): "There may also be instances where public policy warrants differential treatment for men and women. For example, some sex-segregated facilities, such as public restrooms, may be justified by the constitutional right to personal privacy. However, defendants' discriminatory pricing policies are in no way based on privacy considerations, nor are they justified by any other public policy which might warrant differential treatment based on sex. The plain language of the Unruh Act mandates equal provision of advantages, privileges and services in business establishments in this state. Absent a compelling social policy supporting sex-based price differentials, such discounts violate the Act." (Id. at p. 38.)