foo.cc: In function 'bool vsearch(std::vector<int>&, int)':
foo.cc:5:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    5 |         for (int i = 0; i < v.size(); i++)
      |                         ~~^~~~~~~~~~

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