Examples of errors detected by the V703 diagnostic

V703. It is suspicious that the 'foo' field in derived class overwrites field in base class.

ORCT2

V703 It is odd that the 'flags' field in derived class 'RCT12BannerElement' overwrites field in base class 'RCT12TileElementBase'. Check lines: RCT12.h:570, RCT12.h:259. libopenrct2 RCT12.h 570

struct RCT12SpriteBase
{
  ....
  uint8_t flags;
  ....
};
struct rct1_peep : RCT12SpriteBase
{
  ....
  uint8_t flags;
  ....
};

DeepSpeech

V703 It is odd that the 'first_path' field in derived class 'ShortestPathOptions' overwrites field in base class 'ShortestDistanceOptions'. Check lines: shortest-path.h:35, shortest-distance.h:34. shortest-path.h 35

// Base class
template <class Arc, class Queue, class ArcFilter>
struct ShortestDistanceOptions {
  Queue *state_queue;    // Queue discipline used; owned by caller.
  ArcFilter arc_filter;  // Arc filter (e.g., limit to only epsilon graph).
  StateId source;        // If kNoStateId, use the FST's initial state.
  float delta;           // Determines the degree of convergence required
  bool first_path;       // For a semiring with the path property (o.w.
                         // undefined), compute the shortest-distances along
                         // along the first path to a final state found
                         // by the algorithm. That path is the shortest-path
                         // only if the FST has a unique final state (or all
                         // the final states have the same final weight), the
                         // queue discipline is shortest-first and all the
                         // weights in the FST are between One() and Zero()
                         // according to NaturalLess.

  ShortestDistanceOptions(Queue *state_queue, ArcFilter arc_filter,
                          StateId source = kNoStateId,
                          float delta = kShortestDelta)
      : state_queue(state_queue),
        arc_filter(arc_filter),
        source(source),
        delta(delta),
        first_path(false) {}
};
// Derived class
template <class Arc, class Queue, class ArcFilter>
struct ShortestPathOptions
    : public ShortestDistanceOptions<Arc, Queue, ArcFilter> {
  using StateId = typename Arc::StateId;
  using Weight = typename Arc::Weight;

  int32 nshortest;    // Returns n-shortest paths.
  bool unique;        // Only returns paths with distinct input strings.
  bool has_distance;  // Distance vector already contains the
                      // shortest distance from the initial state.
  bool first_path;    // Single shortest path stops after finding the first
                      // path to a final state; that path is the shortest path
                      // only when:
                      // (1) using the ShortestFirstQueue with all the weights
                      // in the FST being between One() and Zero() according to
                      // NaturalLess or when
                      // (2) using the NaturalAStarQueue with an admissible
                      // and consistent estimate.
  Weight weight_threshold;  // Pruning weight threshold.
  StateId state_threshold;  // Pruning state threshold.

  ShortestPathOptions(Queue *queue, ArcFilter filter, int32 nshortest = 1,
                      bool unique = false, bool has_distance = false,
                      float delta = kShortestDelta, bool first_path = false,
                      Weight weight_threshold = Weight::Zero(),
                      StateId state_threshold = kNoStateId)
      : ShortestDistanceOptions<Arc, Queue, ArcFilter>(queue, filter,
                                                       kNoStateId, delta),
        nshortest(nshortest),
        unique(unique),
        has_distance(has_distance),
        first_path(first_path),
        weight_threshold(std::move(weight_threshold)),
        state_threshold(state_threshold) {}
};

Ogre3D

V703 It is odd that the 'mProgramID' field in derived class 'GLGpuNvparseProgram' overwrites field in base class 'GLGpuProgram'. Check lines: OgreGLGpuNvparseProgram.h:63, OgreGLGpuProgram.h:60.

class _OgreGLExport GLGpuProgram : public GpuProgram, public GLGpuProgramBase
{
  // ....
protected:
  GLuint mProgramID; // <=
};
class _OgreGLExport GLGpuNvparseProgram : public GLGpuProgram
{
  // ....

  GLuint getProgramID(void) const
  {
    return mProgramID;            // <=
  }

  // ....
private:
  GLuint mProgramID; // <=
};

Here, the descendant class declares a variable with the same name as the protected variable in the parent class. This leads to name hiding and errors.