I discovered this a few years ago when someone who didn't understand what semver is was trying to do a rails version upgrade for us. They were practically throwing stuff when I got there and explained that lexicographical comparison of the strings would not work. I was about to write my own class for it, but then I thought that since Bundler knew how to resolve deps we should see what it uses. The rest is history!
I use it quite a bit when I have to monkeypatch a gem to backport a fix while I wait for a release:
raise "check if monkeypatch in #{__FILE__} is still needed" if Gem::Version.new(Rails.version) >= Gem::Version.new("8.0.0")
This will blow up immediately when the gem gets upgraded, so we can see if we still need it, instead of it laying around in wait to cause a subtle bug in the future.
The question is: why does the official documentation not mention this, along with guides?
Answer: because documentation is something the ruby core team does not want to think about. It is using scary language after all: English. The bane of most japanese developers. Plus, it is well-documented in Japanese already ... :>
