用指向同一元素的指针包装一个reflect.Value

发布于 2025-01-16 04:39:21 字数 955 浏览 1 评论 0原文

在这里我发现了以下内容代码 -

// ptr wraps the given value with pointer: V => *V, *V => **V, etc.
func ptr(v reflect.Value) reflect.Value {
    pt := reflect.PtrTo(v.Type()) // create a *T type.
    pv := reflect.New(pt.Elem())  // create a reflect.Value of type *T.
    pv.Elem().Set(v)              // sets pv to point to underlying value of v.
    return pv
}

如上所述，对reflect.Value类型的变量V（描述保存数据d的T类型元素）调用此函数，返回reflect.Value类型的变量VP，它描述指向数据的*T类型元素d.

当通过将 VP 的数据设置为 d 以外的值来修改 VP 时，V 不会更改（即通过调用 VP.Set(..)）。
我需要一个如上所述返回 VP 的函数，但是修改 VP 中的数据会修改 V 中的数据。

我需要这个函数的原因是我想扩展这个堆栈溢出答案用默认值初始化字符串和整数。我想使用这个堆栈溢出答案来做到这一点，但为此我需要有一个指针的值运行 SetString 和 SetInt 时，它是结构体，而不是结构体的值。

谢谢，

原文

Here I found the following code -

// ptr wraps the given value with pointer: V => *V, *V => **V, etc.
func ptr(v reflect.Value) reflect.Value {
    pt := reflect.PtrTo(v.Type()) // create a *T type.
    pv := reflect.New(pt.Elem())  // create a reflect.Value of type *T.
    pv.Elem().Set(v)              // sets pv to point to underlying value of v.
    return pv
}

As stated, calling this function on variable V of type reflect.Value, which describes an element of type T that holds data d, returns variable VP of type reflect.Value, which describes an element of type *T that points to data d.

When modifying VP by setting it's data to something other then d, V doesn't change (ie by calling VP.Set(..)).
I need a function that returns VP as described above, but so that modifying the data in VP modifies it in V.

The reason I need this function is that I want to extend this stack overflow answer to initialize strings and ints with default values. I wanted to use this stack overflow answer to do it, but for that I need to have a value of a pointer of a struct, not a value of a struct, when running SetString and SetInt.

Thanks,

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