protocol Protocol { }
enum Enum: Protocol { case `case` }
struct Struct: Protocol { }
class Class: Protocol { }

let enumInstance: Any = Enum.case
let structInstance: Any = Struct()
let classInstance: Any = Class()

print(enumInstance is Protocol) // true, as expected
print(structInstance is Protocol) // true, as expected
print(classInstance is Protocol) // true, as expected

func instanceCheck<TheType>(_ instance: Any, _: TheType.Type) -> Bool {
    return instance is TheType
}

print(instanceCheck(enumInstance, Protocol.self)) // true, as expected
print(instanceCheck(structInstance, Protocol.self)) // true, as expected
print(instanceCheck(classInstance, Protocol.self)) // true, as expected

let enumType: Any.Type = Enum.self
let structType: Any.Type = Struct.self
let classType: Any.Type = Class.self

print(enumType is Protocol.Type) // true, as expected
print(structType is Protocol.Type) // true, as expected
print(classType is Protocol.Type) // true, as expected

func typeCheck<TheType>(_ type: Any.Type, _: TheType.Type) -> Bool {
    return type is TheType.Type
}

print(typeCheck(enumType, Protocol.self)) // false, surprisingly
print(typeCheck(structType, Protocol.self)) // false, surprisingly
print(typeCheck(classType, Protocol.self)) // false, surprisingly