Add detaching an instance from a pool

lib/extlib/pooling.rb

@@ -118,6 +118,10 @@ def release
       @__pool.release(self) unless @__pool.nil?
     end
 
+    def detach
+      @__pool.delete(self) unless @__pool.nil?
+    end
+
     class Pool
       attr_reader :available
       attr_reader :used

spec/pooling_spec.rb

@@ -153,6 +153,13 @@ def dispose
     Extlib::Pooling.scavenger?.should be_false
   end
 
+  it "should be able to detach an instance from the pool" do
+    bob = Person.new('Bob')
+    Person.__pools[['Bob']].size.should == 1
+    bob.detach
+    Person.__pools[['Bob']].size.should == 0
+  end
+
 end
 
 # describe Extlib::Pooling::ResourcePool do