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/bson/util/simple8b.h:272: UNINIT_CTOR 120375 Class member declaration for "_current".
/src/mongo/bson/util/simple8b.cpp:661: UNINIT_CTOR 120375 Non-static class member "_current" is not initialized in this constructor nor in any functions that it calls.
/src/mongo/bson/util/simple8b.h:277: UNINIT_CTOR 120375 Class member declaration for "_mask".
/src/mongo/bson/util/simple8b.cpp:661: UNINIT_CTOR 120375 Non-static class member "_mask" is not initialized in this constructor nor in any functions that it calls.
/src/mongo/bson/util/simple8b.h:287: UNINIT_CTOR 120375 Class member declaration for "_bitsPerValue".
/src/mongo/bson/util/simple8b.cpp:661: UNINIT_CTOR 120375 Non-static class member "_bitsPerValue" is not initialized in this constructor nor in any functions that it calls.
/src/mongo/bson/util/simple8b.h:291: UNINIT_CTOR 120375 Class member declaration for "_countMask".
/src/mongo/bson/util/simple8b.cpp:661: UNINIT_CTOR 120375 Non-static class member "_countMask" is not initialized in this constructor nor in any functions that it calls.
/src/mongo/bson/util/simple8b.h:294: UNINIT_CTOR 120375 Class member declaration for "_countBits".
/src/mongo/bson/util/simple8b.cpp:661: UNINIT_CTOR 120375 Non-static class member "_countBits" is not initialized in this constructor nor in any functions that it calls.
/src/mongo/bson/util/simple8b.h:297: UNINIT_CTOR 120375 Class member declaration for "_countMultiplier".
/src/mongo/bson/util/simple8b.cpp:661: UNINIT_CTOR 120375 Non-static class member "_countMultiplier" is not initialized in this constructor nor in any functions that it calls.
/src/mongo/bson/util/simple8b.h:300: UNINIT_CTOR 120375 Class member declaration for "_selector".
/src/mongo/bson/util/simple8b.cpp:661: UNINIT_CTOR 120375 Non-static class member "_selector" is not initialized in this constructor nor in any functions that it calls.
/src/mongo/bson/util/simple8b.h:303: UNINIT_CTOR 120375 Class member declaration for "_extensionType".
/src/mongo/bson/util/simple8b.cpp:661: UNINIT_CTOR 120375 Non-static class member "_extensionType" is not initialized in this constructor nor in any functions that it calls.