[Go][Reflect] Enforce Pointer & CanSet

main.go

package main

import (
	"fmt"
	"reflect"
)

func EnforcePtr(obj interface{}) (reflect.Value, error) {
	v := reflect.ValueOf(obj)
	if v.Kind() != reflect.Ptr {
		if v.Kind() == reflect.Invalid {
			return reflect.Value{}, fmt.Errorf("expected pointer, but got invalid kind")
		}
		return reflect.Value{}, fmt.Errorf("expected pointer, but got %v type", v.Type())
	}
	if v.IsNil() {
		return reflect.Value{}, fmt.Errorf("expected pointer, but got nil")
	}
	return v.Elem(), nil
}

func canSet(a interface{}) {
	v, err := EnforcePtr(a)
	if err != nil {
		panic(err)
	}

	if v.CanSet() {
		fmt.Println(v.Kind(), " can set")
	} else {
		fmt.Println(v.Kind(), " can't set")
	}
}

func main() {
	i := 0
	canSet(&i)
}