swift_generic.swift

func herd<Animal: Cat> (_ cats: [Animal]) {
    cats.forEach {
        print("Here,cat,  \($0.name)! come here")
    }
}
func herd<Animal: Dog> (_ dogs: [Animal]) {
    dogs.forEach {
        print("Here, dog, \($0.name)! come here")
    }
}
// extension  array
extension Array where Element: Cat {
    func meow() {
        forEach {
        print(" \($0.name) says meows")
        }
    }
}
func herd<Animal: Pet> (_ animal: [Animal]) {
    animal.forEach {
        print("Animal here \($0.name)")
    }
 }

func herd<T:Cat, U:Dog>(_ cats:[T], _ dogs: [U]) {
    cats.forEach {
        print("Here cats: \($0.name)")
    }
    dogs.forEach {
        print("Here dogs: \($0.name)")
    }
}

herd(cats, dogs)
cats.meow()