Sorry, there are a mistake in my text:
>         delete(pAllocator) pBase; //ill-form usage of delete expression
>     In many case we can simulate the action of delete:
>         pBase->~CType();
>         CType* pType=dynamic_cast<CType*>(pBase);
>         operator delete(pType, pAllocator);

It SHOULD be:

         delete(pAllocator) pBase; //ill-form usage of delete expression
     Sometimes we can simulate the action of placement delete, but sometimes
can not, according to the CBaseType class:
     [If CBaseType have at least one virtual function, or say it has a
v-table]
         pBase->~CBaseType();
         void* pVoid=dynamic_cast<void*>(pBase);
         operator delete(pVoid, pAllocator);
     [If CBaseType have no virtual function, and dynamic type of object is
known as CType, and CType inherit CBaseType only one times.]
         pBase->~CBaseType();
         CType* pType=static_cast<CType*>(pBase);
         operator delete(pType, pAllocator);
     [In any other case, the simulation is difficult if not impossible.]



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