F＃：如何编写经典的交换功能？

In C# the classic swap function is:

在C#中,经典的交换功能是:

void swap (ref int a, ref int b){
     int temp = a;
     a = b;
     b = temp;
}

int a = 5;
int b = 10;
swap( ref a, ref b);

How would I write that with F#?

我怎么用F#写这个?

(Note, I do not want the functional equivalent. I actually need pass by reference semantics.)

(注意,我不希望函数等价。我实际上需要通过引用语义传递。)

3 个解决方案

#1

Try the following

请尝试以下方法

let swap (left : 'a byref) (right : 'a byref) =
  let temp = left
  left <- right
  right <- temp

#2

Example to Jared's code:

Jared的代码示例:

let mutable (a, b) = (1, 2)

let swap (left : 'a byref) (right : 'a byref) =
  let temp = left
  left <- right
  right <- temp

printfn "a: %i - b: %i" a b
swap (&a) (&b)
printfn "a: %i - b: %i" a b

Normally, you would use ref-cells instead of mutable let's.

通常,你会使用ref-cells而不是mutable let。

#3

/// A function that swaps the order of two values in a tuple

///一个交换元组中两个值的顺序的函数

let Swap (a, b) = (b, a)

#1