message: Move using namespace declarations
diff: #include <optional>
  #include <string>
  -using namespace eos;
  -using namespace mexplus;
  -
  void mexFunction(int nlhs, mxArray* plhs[], int nrhs, const mxArray* prhs[])
  {
  using std::string;
  + using namespace eos;
  + using namespace mexplus;
  +
  // Check for proper number of input and output arguments:
  int num_input_args = 12;
  int num_output_args = 2;
  