Okay - so you are going to get a bunch of comments to links that address similar sorts of "ATR" (after the revolution) questions (*guys - don't prove me wrong here...*), but also, I don't always follow a barrage of links in the comments section, and think a straight up answer is sometimes helpful (which is one reason I like to engage these questions sometimes)...
Why do we need to know that people in poverty/unable to work will be taken care of in an anarchist future? It isn't anyone's job to do anything in an anarchist future, so the idea that we can know that it will happen is absurd. It might not. It might be horrible, brutal, selfish, which sounds a lot like now.
Granted there are social welfare programs that are created and enforced (taxes levied and dispersed) to help ameliorate the conditions of extreme poverty, but really all they do is maintain a certain level of humane treatment for the poor (similar to how there are laws to ensure the "humane" treatment of animals destined for slaughter houses, or, perhaps more accurately those in entertainment, circuses and zoos). They don't solve the problems at hand, because the problems are those of capitalism and civilization, which are rather beyond the scope of charitable acts to fix.
Ideally charity will no longer be a thing. That doesn't mean people won't help each other, I am sure they would, but charity tends to be a one way street: people give charitably to those in need, as opposed to working together to meet common needs, or actions of solidarity (which is more of a two way street). This is one of those ideas that it took me a bit to wrap my head around, because often the two things look really really similar, but the idea is sort of one of reciprocity, and recognizing oneself as being wrapped up in the struggle of the other (*If anyone else wants to jump in on this and give a better clarification of the anarchist critique of charity, I would welcome it!*).