To me it matters in what kind of club or bar.
I never initiate such questions with men, as that is not relevant.
If someone (a man) asked that in a non-LGBT bar/club, I would tell them to go away.
With women, so not likely to happen and I would never ask because to me it doesn't matter what they have.
If they are Trans, I would only smile and see if they even want to talk.
In an LGBT club/bar, Men don't directly ask as they assume you maybe Pre, But I save them the time and trouble and explain that I may not have what they want. If that is too confusing I just tell them to go away.
If they are cool with that we then can get down to more serious questions.
Again with women and don't assume they are Trans, so I don't ask as it doesn't matter what they have.
If they are a CD, don't really need to ask.
If they are Trans, don't ask as it doesn't matter to me.