planets2.swift

enum Planet: Int {
    case mercury, venus, earth, mars, jupiter, saturn, uranus, neptune
}

struct PlanetOptions {
    let planets: Set<Planet>
    private init(_ planets: Set<Planet>) {
        self.planets = planets
    }

    static let gasGiants = PlanetOptions([.jupiter, .saturn])
    static let rockyPlants = PlanetOptions([.mercury, .venus, .earth, .mars])
}

func myAPIMethod(filter: PlanetOptions) {
    print("call api with filter: \(filter.planets)")
}

myAPIMethod(filter: .rockyPlants)