foo.cc: In function 'int main()':
foo.cc:8:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 |  for(int i=0;i<s.size();i++)
      |              ~^~~~~~~~~
foo.cc:14:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |  for(int j=xb;j<s.size()-1;j++)
      |               ~^~~~~~~~~~~
foo.cc:16:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |  for(int x=0;x<s.size()-1;x++)
      |              ~^~~~~~~~~~~
foo.cc:14:15: warning: 'xb' may be used uninitialized in this function [-Wmaybe-uninitialized]
   14 |  for(int j=xb;j<s.size()-1;j++)
      |               ^

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