foo.cc: In function 'std::vector<int> iadd(std::vector<int>, std::vector<int>)':
foo.cc:11:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |         for(int i = 0; i < v2.size(); i++) {
      |                        ~~^~~~~~~~~~~
foo.cc:15:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |         for(int i = v2.size(); i < v1.size(); i++) {
      |                                ~~^~~~~~~~~~~

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