Since you mention that, rickyrick: My parents regularly put out food and water for their semi-adopted cat, yet she still roams the neighborhood where they live. Turns out four or five families have adopted that same cat, and they also put out food and water.
I think it depends on what options exist for the cat.
Meanwhile, I'm a dog person. We either use containment, or are out with the dogs, or else the dogs are inside with us. I'm less worried about my dogs doing harm, than I am about them encountering fast-moving cars, but I realize that dogs can have radical behavior changes if they hook up with a pack. Best to avoid the whole thing. If one of my dogs does manage to pull a Houdini, their dog tags all have my wife's and my cell phone numbers. (This has come in handy before; some dogs are very creative about getting over or under fences.)
Other than keeping a cat in the house, or a screened porch, or a cat carrier, I don't know of any outdoor enclosure that will reliably contain a cat.