Uninitialized scalar field

The field will contain an arbitrary value left over from earlier computations. A scalar field is not initialized by the constructor
/src/mongo/db/query/optimizer/cascades/memo.h:246: UNINIT_CTOR 127649 Class member declaration for "_heuristicCE".
/src/mongo/db/query/optimizer/opt_phase_manager.cpp:60: UNINIT_CTOR 127649 Non-static class member "_memo._heuristicCE" is not initialized in this constructor nor in any functions that it calls.