Is it possible to dynamically cast a value generated by reflect.Zero/New back to an arbitrary type?
https://blog.golang.org/laws-of-reflection seems to suggest not (as go is statically typed). That pretty much seems to limit the uses of reflection as far as I can see, as you always need to be aware of the type you are working with.
Here's an example of what I mean:
package main
import (
"fmt"
"reflect"
)
type A struct {
Name string
}
func main() {
a := &A{Name: "Dave"}
fmt.Println(a)
//create a nil pointer of an arbitrary type
dynamicType := reflect.TypeOf(a)
dynamicNil := reflect.Zero(dynamicType).Interface()
a = dynamicNil //is it possible to do this without explicitly casting to A (ie. avoiding `a = dynamicNil.(*A)`)
fmt.Println(a)
}
Your question's prose and code contradict.
In your code, dynamicNil
has the type interface{}
, not reflect.Value
as the prose suggests. As a
has concrete type *A
you'll have to type-assert dynamicNil
to *A
. There's no way around that.
Also note that Go doesn't have casts -- only type-conversions and assertions.
Edit: maybe you're looking for reflect.Value.Set
? it's unclear to me.
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