如何将Swift不透明类型与文字结合使用？

protocol Printable {
    func printDescription() -> String
}

struct Person: Printable {
    var name: String
    var age: Int
    
    func printDescription() -> String {
        return "Name: \(name), Age: \(age)"
    }
}

func createPrintable() -> some Printable {
    return Person(name: "John", age: 25)
}

let printable = createPrintable()
let description = "Person Description: \(printable.printDescription())"
print(description)