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/exec/plan_stats.h:778: UNINIT_CTOR 117857 Class member declaration for "docsRejected".
/src/mongo/db/exec/plan_stats.h:757: UNINIT_CTOR 117857 Non-static class member "docsRejected" is not initialized in this constructor nor in any functions that it calls.