reflection - Convert reflect.value to reflect.method -

i have fallowing:

func newmethoddescriptor(typ interface{}) *methoddescriptor {      reflectedmethod := reflect.valueof(typ)     methodtype := reflectedmethod.type     paramcount := methodtype.numin() - 1     ... 

but when try:

newmethoddescriptor(func(){}) 

i compile time error:

methodtype.numin undefined (type func() reflect.type has no field or method numin)