SortedSet implements a Set whose elements are sorted in ascending order (according to the return values of their <=> methods) when iterating over them.

Every element in SortedSet must be mutually comparable to every other: comparison with <=> must not return nil for any pair of elements. Otherwise ArgumentError will be raised.

Currently this library does nothing for JRuby, as it has its own version of Set and SortedSet.


Add this line to your application's Gemfile:

gem 'sorted_set'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install sorted_set


require "sorted_set"

set =[2, 1, 5, 6, 4, 5, 3, 3, 3])
ary = []

set.each do |obj|
  ary << obj

p ary # => [1, 2, 3, 4, 5, 6]

set2 =[1, 2, "3"])
set2.each { |obj| } # => raises ArgumentError: comparison of Fixnum with String failed


After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.


Bug reports and pull requests are welcome on GitHub at


The gem is available as open source under either the terms of the 2-Clause BSD License.