I find my local library does that fairly well. Also, "approximately all computer science and programming books"? Approximately all? Just how good an approximat

I find my local library does that fairly well. Also, "approximately all computer science and programming books"? Approximately all? Just how good an approximation is that? I can't help but think a pretty bad one. Maybe "a few books on approximately most of the top fifty or so languages and a bunch of books on fairly common techniques, tools and systems"? Sure, if you just need any book on something, it's going to be something fairly common and they've probably got one.