/in/foo.cc: In member function 'void Persons::Output()':
/in/foo.cc:55:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Person*>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |         for(int i=0;i<vec.size();i++){
      |                     ~^~~~~~~~~~~
/in/foo.cc: In destructor 'Persons::~Persons()':
/in/foo.cc:63:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Person*>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |         for(int i=0;i<vec.size();i++){
      |                     ~^~~~~~~~~~~