Hello, If anybody is able to make shifted_ptr<> break, please share the replication test. It looks to be working fine but the possibility of having something I forgot could still be present. To give everybody a quick idea on the different states both the pointer and the pointee will have are defined as such: shifted_ptr<> (pointer): - part of the pool (local heap) - part of anything else (stack, data, system heap) shifted<> (pointee): - initialized - uninitialized When the shifted<> is initialized it means it knows what "set" it belongs to. If it is uninitialized it means it is still part of a construction sequence that is not yet finalized, hence not yet attached to any "set". Please disregard anything related to shifted_allocator<> because this is of pure shifted_ptr<> concerns. Some test examples can be found at: https://svn.boost.org/svn/boost/sandbox/shifted_ptr/libs/smart_ptr/example/ Regards, -Phil