通过参考作为参数传递不同类型的变量，将变量转换为同一variadic参数

发布于 2025-02-10 12:43:03 字数 760 浏览 2 评论 0原文

我一直在与 golang 缺乏可选参数的困难，所以我一直在使用最接近的解决方法：variadics。即使我使它起作用，但试图通过参考将多种变量类型传递到相同的variadic参数是凌乱的：

// back-end
func UpdateRef(variadic ...*interface{}) {
    for _, v := range variadic {
        if v.(type) == string {
            *v = "New ref val"
        }
    }
}

// front-end
func Interface(x interface{}) interface{} { return &x }
func main() {
    ref := Interface("Hey") // starts as "Hey"
    i := Interface(500)
    UpdateRef(&ref, &i) // ends at "New ref val"
}

替换前端

// front-end
func main() {
    ref := "Hey" // starts as "Hey"
    UpdateRef(ref, 500) // ends at "New ref val"
}

如果我用以下方式前端代码工作？只要所需的前端运行，后端就可以像需要一样详细。这可能吗？如果没有，是否需要一种优雅的解决方案，需要对所需的前端进行最小的变化？

原文

I've been struggling with golang's lack of optional parameters, so I have been using the closest workaround: variadics. Even though I got it working, it is messy attempting to pass multiple variable types to the same variadic parameter by reference:

// back-end
func UpdateRef(variadic ...*interface{}) {
    for _, v := range variadic {
        if v.(type) == string {
            *v = "New ref val"
        }
    }
}

// front-end
func Interface(x interface{}) interface{} { return &x }
func main() {
    ref := Interface("Hey") // starts as "Hey"
    i := Interface(500)
    UpdateRef(&ref, &i) // ends at "New ref val"
}

If I replace the front-end with this:

// front-end
func main() {
    ref := "Hey" // starts as "Hey"
    UpdateRef(ref, 500) // ends at "New ref val"
}

...then how could I change the back-end to make the desired front-end code work? The back-end can be as verbose as need be, so long as the desired front-end runs as is. Is this possible? If not, is there an elegant solution that requires minimal changes to the desired front-end?

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

溇涏 2025-02-17 12:43:03

使用接口{}作为参数类型。键入指针类型。
取消指针设置值。

func UpdateRef(variadic ...interface{}) {
    for _, v := range variadic {
        if v, ok := v.(*string); ok {
            *v = "New ref val"
        }
    }
}

将指针传递到功能：

ref := "Hey"
i := 500
UpdateRef(&ref, &i)
fmt.Println(ref)  // prints “New ref val”

Use interface{} as the argument type. Type assert to pointer types.
Dereference pointers to set the values.

func UpdateRef(variadic ...interface{}) {
    for _, v := range variadic {
        if v, ok := v.(*string); ok {
            *v = "New ref val"
        }
    }
}

Pass pointers to the function:

ref := "Hey"
i := 500
UpdateRef(&ref, &i)
fmt.Println(ref)  // prints “New ref val”

回复收藏 0 原文

空心↖ 2025-02-17 12:43:03

您只需

package main

import (
    "reflect"
)

// back-end
func UpdateRef(variadic ...interface{}) {
    for _, v := range variadic {
        kind := reflect.TypeOf(v).Kind()
        if kind == reflect.Pointer {
            reflect.ValueOf(v).Elem().Set(reflect.ValueOf("New ref val"))
        }
    }
}

// front-end
func main() {
    ref := "Hey"         // starts as "Hey"
    // To modify a reflection object, the value must be settable.
    UpdateRef(&ref, 500) // ends at "New ref val"
    println(ref)
}

查看Golang博客： https://go.dev/blog/laws/laws-og/laws-og-laws-er-laws-er-laws-of--------反射。

编码快乐！

you just

package main

import (
    "reflect"
)

// back-end
func UpdateRef(variadic ...interface{}) {
    for _, v := range variadic {
        kind := reflect.TypeOf(v).Kind()
        if kind == reflect.Pointer {
            reflect.ValueOf(v).Elem().Set(reflect.ValueOf("New ref val"))
        }
    }
}

// front-end
func main() {
    ref := "Hey"         // starts as "Hey"
    // To modify a reflection object, the value must be settable.
    UpdateRef(&ref, 500) // ends at "New ref val"
    println(ref)
}

check out the golang blog:https://go.dev/blog/laws-of-reflection.

Coding Happy!

回复收藏 0 原文

~没有更多了~