mjtko · May 4, 2012 20:29 · May 4, 2012
diff --git a/set_subset_ext.rb b/set_subset_ext.rb
@@ -0,0 +1,11 @@
+require 'set'
+
+class Set
+  def subset(&pred)
+    Set.new.tap do |subset|
+      each do |x|
+        subset << x if pred.call(x)
+      end
+    end
+  end
+end