Depends on the way the law is written. Here in CO, "no guns allowed" signs mean jack. The law gives you the right to carry no matter what the property owner has posted. The property owner is in his right to ask you to leave because you have a firearm, and if you refuse can get you on trespassing charges but not on gun charges.

The only exception is if everyone who enters a building is searched or goes through a metal detector, say at a sporting event or concert. Then you can be found liable for carrying a firearm where it isn't allowed, as you should "have a reasonable expectation of safety" in a place where everyone is screened. The law understands that "no guns allowed" signs do not provide a reasonable expectation of safety.

We can also carry in a place that serves alcohol, and -- as near as I can tell-- there are no provisions banning the consumption of alcohol while carrying. Though I'm sure any jury wouldn't look favorably on a CCW holder drinking while carrying.