I've dated both kinds of guys... those that are more traditional and those that are more progressive. Usually I've asked them long before going out to eat... however I have been caught off guard a few times.
During these times... I ALWAYS bring my wallet with the intention of paying for my meal - even the whole meal. This gives me a sense of confidence during the meal... leaves me with the feeling that I'm not taking advantage of the guy, and the food we are enjoying is within my price range. If the guy asked me out, then usually he pays for the meal - I don't argue if he offers to cover the meal. I thank him for he was an exceptionally generous man... Other times, when I ask them out... I pay for the meal (though I've had a couple of guys either offer to pay for the meal anyways... or try to split it). If I feel I am returning the favor for a previously shared meal, then I will politely refuse their intention to pay for the second meal (which I invited them to). During meals in which we both decided to go out to eat... the meal can be split or it's a matter of who's the sneakiest in rushing to pay for it (usually without the other being aware).
From my experience, it is usually best not to eat at places you feel you couldn't afford... and a good idea to bring along your own money - even if you do not pay for your meal - just to give you the added confidence. The guy will usually pick up on this... and I've noticed a sense of ease in them. So this all subtly adds to the pleasantness of the outing... and puts you in a positive light with the guy (i.e. he realizes you're not there for just a free meal).
"The weakest soul, knowing its own weakness, and believing this truth that strength can only be developed by effort and practice, will, thus believing, at once begin to exert itself, and, adding effort to effort, patience to patience, and strength to strength, will never cease to develop, and will at last grow divinely strong."
- James Allen