Scala在Predef中有一个通用的identity函数:
def identity[A](x: A): A
Kotlin 在标准图书馆有类似的设施吗？当然，我可以简单地使用{ it }，但我发现identity更容易阅读，实例化所有这些lambda有点浪费.
I must be able to use this identity function in places where a function (Foo) -> Foo is expected, for any type Foo. Is such a function even possible in Kotlin's type system? (In the case of Scala, there is an implicit conversion that wraps the method inside a function object or something.)