英文:
go reflect: how to dynamically create a pointer to a pointer to ...?
问题
我想创建一个表示多级嵌套指向最终值的reflect.Value。嵌套级别在编译时是未知的。如何使用reflect创建指向指针的指针？
当我尝试创建指向指针的指针时，我已经遇到了"不可寻址的值"障碍。
dave := "It's full of stars!"
stargazer := reflect.ValueOf(&dave)
stargazer = stargazer.Addr() // 报错：reflect.Value.Addr of unaddressable value
对于stargazer.UnsafeAddr()等也是一样。虽然stargazer.Elem().UnsafeAddr()等可以工作，但我看不出这如何帮助（递归地）创建一个新的非零指向指针的指针...
英文:
I would like to create a reflect.Value that represents a multiple-level nested pointer to a final value. The nesting level is not known at compile time. How can I create pointers to pointers using reflect?
I already stumble at the "unaddressable value" hurdle when trying to create a pointer to a pointer.
dave := "It's full of stars!"
stargazer := reflect.ValueOf(&dave)
stargazer = stargazer.Addr() // panic: reflect.Value.Addr of unaddressable value
Same for stargazer.UnsafeAddr(), etc. While stargazer.Elem().UnsafeAddr() etc. works, I can't see how this helps in (recursively) creating a new non-zero pointer to a pointer...
答案1
得分: 4
使用以下代码来创建指向stargazer值的指针。
p := reflect.New(stargazer.Type())
p.Elem().Set(stargazer)
// p.Interface() 是指向 stargazer.Interface() 值的指针
示例：
dave := "它充满了星星！"
stargazer := reflect.ValueOf(dave)
for i := 0; i < 10; i++ {
p := reflect.New(stargazer.Type())
p.Elem().Set(stargazer)
stargazer = p
}
fmt.Printf("%T\n", stargazer.Interface()) // 输出 **********string
请注意，这只是代码的翻译部分，不包括任何其他回答或问题。
英文:
Use the following code to create a pointer to the value in stargazer.
p := reflect.New(stargazer.Type())
p.Elem().Set(stargazer)
// p.Interface() is a pointer to the value stargazer.Interface()
Example:
dave := "It's full of stars!"
stargazer := reflect.ValueOf(dave)
for i := 0; i < 10; i++ {
p := reflect.New(stargazer.Type())
p.Elem().Set(stargazer)
stargazer = p
}
fmt.Printf("%T\n", stargazer.Interface()) // prints **********string
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