f# - 我如何正确重写一个受约束的方法

如何覆盖以下代码中的Zero方法，以便可以为Euro(0)中的定义返回type Euro

[<AbstractClass>]
type Currency () =
    abstract member Zero<'T when 'T :> Currency > : unit -> 'T

type Euro (value: int) =
    inherit Currency()
    member this.Value = value
    override this.Zero() = Euro(0) :> _

最佳答案

您是否尝试过将通用约束提升到类级别？

[<AbstractClass>]
type Currency<'T when 'T :> Currency<'T>>() =
    abstract member Zero : unit -> 'T

type Euro (value: int) =
    inherit Currency<Euro>()
    member this.Value = value
    override this.Zero() = Euro(0)

尽管自引用泛型在我看来总是很奇怪，但这是在C#中完成的方式。

关于f# - 我如何正确重写一个受约束的方法，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/42253991/