How to initialize an empty pointer by reflect

Question

This is a very straight forward question.

How do you implement Initialize() below with reflect ? Or is this possible?

func Initialize(v interface{}) {
    // ... some reflection code
}

type MyType struct {
    Name string
}

func main() {
    var val *MyType

    // val is nil before initialize
    Initialize(val)
    // val is now &MyType{Name: ""}

    // ...
}

```

Answer 1

Here's how to do it:

func Initialize(v interface{}) {
  rv := reflect.ValueOf(v).Elem()
  rv.Set(reflect.New(rv.Type().Elem()))
}

This function must be called with a pointer to the value to set:

Initialize(&val)

playground example

The code in this answer panics if the argument type is not a pointer to a pointer. Depending on your use, you might want to check the reflect value kind before calling Elem().