message: remove std:next(.., 0) for the simpler form
diff: @@ -2584,7 +2584,7 @@ size_t relative_to_absolute_step(core::Variable<T> *variable,
  {
  const std::map<size_t, std::vector<size_t>> &indices =
  variable->m_AvailableStepBlockIndexOffsets;
  - auto itStep = std::next(indices.begin(), 0);
  + auto itStep = indices.begin();
  size_t absstep = itStep->first - 1;
  for (int step = 0; step < relstep; step++)
  @@ -2608,7 +2608,7 @@ Dims get_global_array_signature(core::Engine *fp, core::IO *io,
  // is not supported by a simple API function
  const std::map<size_t, std::vector<size_t>> &indices =
  variable->m_AvailableStepBlockIndexOffsets;
  - auto itStep = std::next(indices.begin(), 0);
  + auto itStep = indices.begin();
  for (int step = 0; step < nsteps; step++)
  {
  