SortedSet implements a Set that guarantees that it's element are yielded in sorted order (according to the return values of their #<=> methods) when iterating over them.

All elements that are added to a SortedSet must respond to the <=> method for comparison.

Also, all elements must be mutually comparable: el1 <=> el2 must not return nil for any elements el1 and el2, else an ArgumentError will be raised when iterating over the SortedSet.

Example

require "set"

set = SortedSet.new([2, 1, 5, 6, 4, 5, 3, 3, 3])
ary = []

set.each do |obj|
  ary << obj
end

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

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