``` fun bindView position Int view ListItemView Interface =

Question

``` fun bindView position Int view ListItemView Interface = when ViewTypeEnum values position ENUM1 gt bindViewType1 view as ViewType1 ENUM2 gt bindViewType2 view as ViewType2 ```

Andreas Sinz · Answer

< andreworobator> What does the whole class look like

louiscad · Answer

Get rid of this enum and the `values ` call It allocates a new array defensive copy each time you call it

andreworobator · Answer

Do you have an alternative for ensuring type safety I m willing to allocate a new array to ensure type safety because the performance hit is negligible

Andreas Sinz · Answer

we need more information to really give you a good solution post the whole class for exampel

louiscad · Answer

< andreworobator> Actually in this case the performance hit may not be that negligible on a low end phone where you scroll very fast because it is in a recyclerview that can bind a lot of items per seconds

louiscad · Answer

< andreworobator> My recyclerview view types are not type safe but it doesn t matter I check by hand I handle it properly It s all in one class with only 2 3 usages after all

andreworobator · Answer

< louiscad> Thanks for the insight you definitely don t want to be doing allocations every time you re binding a view I ve modified my code to avoid instantiating a new array every time ``` fun bindView position Int view ListItemView = when ViewTypeEnum values position ENUM1 gt bindViewType1 view as ViewType1 ENUM2 gt bindViewType2 view as ViewType2 class ViewTypeEnum ENUM1 ENUM2 companion object val values Array lt ViewTypeEnum gt = ViewTypeEnum values ```

louiscad · Answer

< andreworobator> I guess you meant `enum class` with a ` ` after the last enum value `ENUM2` but yes such code is better thumbsup You could also add ` JvmField` to `values` wink

andreworobator · Answer

< louiscad> The code I posted was a scrubbed down version to remove domain specific details The real code compiles I promise haha This project is 100 kotlin so I don t do interop code slightly smiling face Thanks again for the help

louiscad · Answer

< andreworobator> ` JvmField` is for performance not for interop You can make your enum class private BTW

andreworobator · Answer

< louiscad> How does ` JvmField` improve performance

louiscad · Answer

< andreworobator> Saves a method call getter which still has a bit more overhead over a field access on dalvik VM or ART

andreworobator · Answer

Awesome thanks again < louiscad>

Andreas Sinz · Answer

btw your code is not typesafe it can still fail at runtime without the compiler being able to tell you that you are doing something wrong