英文:
How to set any value to interface{}
问题
我有以下代码：
package mainimport ("fmt")type Point struct {x,y int}func decode(value interface{}) {fmt.Println(value) // -> &{0,0}// 这是一个简化的例子，实际上可以是任何类型的值，而不仅仅是Point类型的值。value = &Point{10,10}}func main() {var p = new(Point)decode(p)fmt.Printf("x=%d, y=%d", p.x, p.y) // -> x=0, y=0，期望结果是x=10, y=10}
我想将任何类型的值设置为传递给decode函数的值。在Go中是否可能，或者我理解错了什么？
http://play.golang.org/p/AjZHW54vEa
英文:
I have following code:
package mainimport ("fmt")type Point struct {x,y int}func decode(value interface{}) {fmt.Println(value) // -> &{0,0}// This is simplified example, instead of value of Point type, there// can be value of any type.value = &Point{10,10}}func main() {var p = new(Point)decode(p)fmt.Printf("x=%d, y=%d", p.x, p.y) // -> x=0, y=0, expected x=10, y=10}
I want to set value of any type to the value passed to decode function. Is it possible in Go, or I misunderstand something?
答案1
得分: 5
通用地，只能使用反射：
package mainimport ("fmt""reflect")type Point struct {x, y int}func decode(value interface{}) {v := reflect.ValueOf(value)for v.Kind() == reflect.Ptr {v = v.Elem()}n := reflect.ValueOf(Point{10, 10})v.Set(n)}func main() {var p = new(Point)decode(p)fmt.Printf("x=%d, y=%d", p.x, p.y)}
英文:
Generically, only using reflection:
package mainimport ("fmt""reflect")type Point struct {x, y int}func decode(value interface{}) {v := reflect.ValueOf(value)for v.Kind() == reflect.Ptr {v = v.Elem()}n := reflect.ValueOf(Point{10, 10})v.Set(n)}func main() {var p = new(Point)decode(p)fmt.Printf("x=%d, y=%d", p.x, p.y)}
答案2
得分: 1
我不确定你的确切目标。
如果你想要断言value是一个指向Point的指针并对其进行更改，你可以这样做：
func decode(value interface{}) {p := value.(*Point)p.x = 10p.y = 10}
英文:
I'm not sure of your exact goal.
If you want to assert that value is a pointer to Point and change it, you can do that :
func decode(value interface{}) {p := value.(*Point)p.x=10p.y=10}
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