int64不支持LanguagePrimitives.DivideByInt？

Question

为什么int64不支持LanguagePrimitives.DivideByInt？我认为写这样的东西是很自然的:

let inline DivBy2 n = LanguagePrimitives.DivideByInt n 2
let res = DivBy2 100L

但编译器说int64 doesn't support the operator DivideByInt.

我试图欺骗:

type System.Int64 with 
    static member DivideByInt (n: System.Int64) (d: int) = n / (int64 d)

但它不起作用.

通过int执行int64的泛型划分可以做些什么？

Answer 1

看看F#源代码,int64类型不包含在函数中DivideByInt,我不知道为什么.

您可以定义另一个通用函数,如下所示:

open LanguagePrimitives
type DivExtension = DivExtension of int with
    static member inline (=>) (x             , DivExtension y) = DivideByInt x y
    static member        (=>) (x:int64       , DivExtension y) = x / (int64 y)
    static member        (=>) (x:DivExtension, DivExtension y) = x

let inline DivByInt x y = x => DivExtension y

或者您甚至可以隐藏原始DivideByInt功能:

let inline DivideByInt x y = x => DivExtension y

请注意,您还可以添加更多重载(即对于int),在这种情况下,您不需要最后一个"虚拟"重载来推断正确的签名.