Question about sudoku batch client design: verify() placeholder and succeed counter

[ipython3]

Hi, I have a design question about the Sudoku example.

While building the target muduo/examples/sudoku/batch.cc, I noticed:

verify() always returns true:

bool verify(const string& result)
{
  return true;
}

In runLocal(), succeed is incremented but never used:

void runLocal(std::istream& in)
{
  Timestamp start(Timestamp::now());
  std::string line;
  int count = 0;
  int succeed = 0;
  while (getline(in, line))
  {
    if (line.size() == implicit_cast<size_t>(kCells))
    {
      ++count;
      if (verify(solveSudoku(line)))
      {
        ++succeed;
      }
    }
  }
  double elapsed = timeDifference(Timestamp::now(), start);
  printf("%.3f sec, %.3f us per sudoku.\n", elapsed, 1000 * 1000 * elapsed / count);
}

On my setup (with warnings treated as errors), this triggers:

error: variable 'succeed' set but not used [-Werror,-Wunused-but-set-variable]

My questions:

• Is verify() intentionally a placeholder?
• If yes, what kind of verification was intended here?
• Is the intended philosophy for batch/pipeline/loadtest to be “pure performance benchmark first” (minimal validation), or should correctness verification be part of the benchmark client?
• Would you prefer removing succeed, printing it, or implementing verify in this example?

I am mostly trying to understand the original intent of this example design. Thanks!