所以你实际上需要创建一个StringFormat，它的函数类型如下

So you actually need to create a StringFormat which has a function type as follows

> sprintf (Printf.StringFormat<string->string>("Hello %s")) "World";;
  val it : string = "Hello World"

在 6.3.16 的规范，显示了一个例子.

In Section 6.3.16 of the spec, an example of this is shown.