foo.cc: In function 'int main()':
foo.cc:158:35: warning: value computed is not used [-Wunused-value]
  158 |     freopen("in.txt", "r", stdin) != nullptr;
      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
foo.cc:159:37: warning: value computed is not used [-Wunused-value]
  159 |     freopen("out.txt", "w", stdout) != nullptr;
      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~

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