funny enough this possible memory corruption
didn't happen in the unit test, because my
compiler optimised the additional int field
of class SubDummy, making it the same size
of the baseclass. Now matters should be safe.
this turns out to be the typical usage scenario
for ScopedCollection: a manager object owning
the collection will populate it with specially
crafted components and invoke a member function
for creating the individual components.
This shortcut avoids using tr1::bind alltogether