message: COMP: remove warnings due to unhandled enum value
  Warning introduced by
diff: @@ -287,6 +287,8 @@ SetBackProjectionFromGgo(const TArgsInfo & args_info, TIterativeReconstructionFi
  {
  switch (args_info.bp_arg)
  {
  + case (-1): // bp__NULL, keep default
  + break;
  case (0): // bp_arg_VoxelBasedBackProjection
  recon->SetBackProjectionFilter(TIterativeReconstructionFilter::BP_VOXELBASED);
  break;
  @@ -322,6 +324,8 @@ SetForwardProjectionFromGgo(const TArgsInfo & args_info, TIterativeReconstructio
  {
  switch (args_info.fp_arg)
  {
  + case (-1): // fp__NULL, keep default
  + break;
  case (0): // fp_arg_Joseph
  recon->SetForwardProjectionFilter(TIterativeReconstructionFilter::FP_JOSEPH);
  break;
  