code: func MakeInto(ptrTo interface{}, from interface{}) {
  	fromSliceValue := reflect.ValueOf(from)
  	fromLen := fromSliceValue.Len()
  	if fromLen == 0 {
  		return
  	}
  	// Deref the pointer to slice.
  	slicePtrValue := reflect.ValueOf(ptrTo)
  	if slicePtrValue.Kind() != reflect.Ptr {
  		panic("destination is not a pointer")
  	}
  	destSliceValue := slicePtrValue.Elem()
  	// The type of the elements of the destination slice.
  	destSliceElemType := destSliceValue.Type().Elem()
  	destSliceValue.Set(reflect.MakeSlice(destSliceValue.Type(), fromLen, fromLen))
  	for i := range iter.N(fromSliceValue.Len()) {
  		// The value inside the interface in the slice element.
  		itemValue := fromSliceValue.Index(i)
  		if itemValue.Kind() == reflect.Interface {
  			itemValue = itemValue.Elem()
  		}
  		convertedItem := itemValue.Convert(destSliceElemType)
  		destSliceValue.Index(i).Set(convertedItem)
  	}
  }
docs: // Makes and sets a slice at *ptrTo, and type asserts all the elements from
  // from to it.