What does tilde-greater-than (~>) mean in Ruby gem dependencies?
ruby, rubygems
Solution
It means "equal to or greater than in the last digit", so e.g. `~> 2.3` means "equal to 2.3 or greater than 2.3, but less than 3.0", while `~> 2.3.0` would mean "equal to 2.3.0 or greater than 2.3.0, but less than 2.4.0".
You can pronounce it as "approximately greater than".
§ Pessimistic version constraint
Problem
What does `~>` mean in the context of Ruby gem depenedencies? For example, when opening a legacy project in the RubyMine IDE, I get this message ``` Gems required for project are not attached: arel (~> 2.0.2), rspec-expectation (~> 2.5.0)... ``` I've seen this tilde-greater-than notation elsewhere in the Ruby world (it's not specific to RubyMine). Does this operator have a name other than the awkward-sounding tilde-greater-than?