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/s/commands/cluster_write_cmd.h:127: UNINIT_CTOR 121924 Class member declaration for "_bypass".
/src/mongo/s/commands/cluster_write_cmd.h:81: UNINIT_CTOR 121924 Non-static class member "_bypass" is not initialized in this constructor nor in any functions that it calls.