Regarding the move Stealth Rock, what happens if the opponent switches out?

Question

Okay here is the Scenario

My Steelix's has survived a Fire Blast

Its Custap Berry activates ensuring he gets the next attack

I choose Stealth Rock, but the Opponent Switches Out!

What happens? does the Stealth Rock set? or miss?

Answer 1

Stealth Rock does not "attack" the opponent, it lays a trap of stones around them so that any Pokemon get hurt when switching in.

Using a Custap Berry makes the holder go first in the same "priority bracket". So Stealth Rock would go before the opponent used a regular attack. However, switching out is +6 priority and will always happen before you use Stealth Rock.

The opponent will switch, then you lay the rocks. It will not injure the opponent then because they already switched in. But when they next switch out, it will hurt them.

Answer 2

The opponent will still go before you, and it will set up after the next pokemon comes in.

So Stealth Rocks will still set.