switch-on: when the selector value is determined after the data
When selector variable for switch-on: determinate before data we see this:
![1](https://user-images.githubusercontent.com/431985/62747887-bcb12780-ba99-11e9-99b7-d4e70bf0b978.png)

zamerValues is a struct of zamer_pq type.

but if selector variable determinate before data we see this:
![2](https://user-images.githubusercontent.com/431985/62747966-26313600-ba9a-11e9-9c0d-0d9967a25d6f.png)

zamerValues is a byte array.

How can I determine the switch-on type correctly when the selector  variable is located after the data itself?