Index: boost/make_shared.hpp
===================================================================
--- boost/make_shared.hpp	(revision 50653)
+++ boost/make_shared.hpp	(working copy)
@@ -60,6 +60,11 @@
     {
     }
 
+    // this copy constructor is an optimization: we don't need to copy the storage_ member,
+    // and shouldn't be copying anyways after initialized_ becomes true
+    sp_ms_deleter(const sp_ms_deleter &other): initialized_( false )
+    {}
+
     ~sp_ms_deleter()
     {
         destroy();