methodmissing · June 18, 2009 11:05 · Jun 18, 2009
diff --git a/gistfile1.rb b/gistfile1.rb
@@ -0,0 +1,47 @@
+require 'rubygems'
+require 'active_support'
+require "rbench"
+
+class Hash
+
+  def fast_reverse_merge( other_hash )
+    self.merge( other_hash ){|k,o,n| o }
+  end
+
+  def fast_reverse_merge!( other_hash )
+    self.merge!( other_hash ){|k,o,n| o }
+  end
+
+end
+
+first = { :one => 1, :two => 2 }
+second = { :three => 3, :four => 4 }
+
+RBench.run(10_000) do
+
+  report "Hash#reverse_merge!" do
+    first.reverse_merge!( second )
+  end
+
+  report "Hash#fast_reverse_merge!" do
+    first.fast_reverse_merge!( second )
+  end
+
+  report "Hash#reverse_merge" do
+    first.reverse_merge( second )
+  end
+
+  report "Hash#fast_reverse_merge" do
+    first.fast_reverse_merge( second )
+  end
+
+end  
+
+=begin
+                                 Results |
+------------------------------------------
+Hash#reverse_merge!                0.035 |
+Hash#fast_reverse_merge!           0.018 |
+Hash#reverse_merge                 0.020 |
+Hash#fast_reverse_merge            0.031 |
+=end