foo.cc: In function 'void out(int, int, std::string&)':
foo.cc:7:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    7 |     if (a+b>s.length())
      |         ~~~^~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:20:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |     if (a>s.length())
      |         ~^~~~~~~~~~~

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