如何在F＃中为自定义类型定义一元减号？

Question

如何在F＃中为自定义类型定义-x？

这将抱怨它期望一个元组：

type Vector2<'T> = 
  | Vector2 of 'T * 'T
  with
    static member inline (-) (Vector2 (x, y)) =
      Vector2 (-x, -y)

Answer 1

您需要将~字符添加到运算符定义中。

static member inline (~-) (Vector2 (x, y)) = Vector2 (-x, -y)

这将告诉编译器是一元运算符。