there is somewhat of a cardinal rule in rio de janeiro that swimwear remains designated for beach areas - it is definitely not out of the ordinary for many beachgoers in ipanema, copacabana, and leblon to visit the busy shopping areas nearby but it is recommended, and even required in most establishments, that one be covered upon entry. 

anyone who is looking to use a public restroom, at a facility that does not require visitors to be customers, should always carry a top and bottom with them so they can cover up before entering the area - Men are usually prohibited from being shirtless and are required to wear t-shirts, as well as women who must cover up bikini tops.