pointers - reflect.New returns <nil> instead of initialized struct -


i using reflection library i'm building there's don't understand reflect.new.

type struct {     int     b string }  func main() {      real := new(a)     reflected := reflect.new(reflect.typeof(real)).elem().interface()     fmt.println(real)     fmt.println(reflected) }

gives:

$ go run *go &{0 } <nil>

isn't reflect.new supposed return &{0 } too? (runnable version)

ultimately, wish able iterate on fields of reflected struct (reflected.numfield() gives reflected.numfield undefined (type interface {} interface no methods)) , use setint, setstring , on.

thanks,

you used builtin new() function when created real variable, returns pointer! type of real *a, not a! source of confusion.

reflect.new() returns pointer (zeroed) value of given type (wrapped in reflect.value). if pass type a, wrapped *a, a initialized / zeroed. if pass type *a, wrapped **a, *a initialized (zeroed), , 0 value pointer type nil.

you ask reflect.new() create new value of pointer type (*a), , –as mentioned– 0 value nil.

you have pass type a (and not type *a). works (try on go playground):

real := new(a) reflected := reflect.new(reflect.typeof(real).elem()).elem().interface() fmt.println(real) fmt.println(reflected)

or (go playground):

real := a{} reflected := reflect.new(reflect.typeof(real)).elem().interface() fmt.println(real) fmt.println(reflected)

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