/in/foo.cc: In function 'int main()':
/in/foo.cc:12:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |         for(int i=0;i<s1.size();i++)
      |                     ~^~~~~~~~~~
/in/foo.cc:14:22: 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 i=0;i<s2.size();i++)
      |                     ~^~~~~~~~~~
/in/foo.cc:16:24: error: no match for 'operator-' (operand types are 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'std::string' {aka 'std::__cxx11::basic_string<char>'})
   16 |         cout<<s1.size()-a<<' '<<s2.size()-a0;
      |               ~~~~~~~~~^~
      |                      |  |
      |                      |  std::string {aka std::__cxx11::basic_string<char>}
      |                      std::__cxx11::basic_string<char>::size_type {aka long unsigned int}
In file included from /usr/include/c++/12/string:47,
                 from /usr/include/c++/12/bits/locale_classes.h:40,
                 from /usr/include/c++/12/bits/ios_base.h:41,
                 from /usr/include/c++/12/ios:42,
                 from /usr/include/c++/12/istream:38,
                 from /usr/include/c++/12/sstream:38,
                 from /usr/include/c++/12/complex:45,
                 from /usr/include/c++/12/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/12/bits/stdc++.h:54,
                 from /in/foo.cc:1:
/usr/include/c++/12/bits/stl_iterator.h:621:5: note: candidate: 'template<class _IteratorL, class _IteratorR> decltype ((__y.base() - __x.base())) std::operator-(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  621 |     operator-(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/12/bits/stl_iterator.h:621:5: note:   template argument deduction/substitution failed:
/in/foo.cc:16:25: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'}
   16 |         cout<<s1.size()-a<<' '<<s2.size()-a0;
      |                         ^
/usr/include/c++/12/bits/stl_iterator.h:1778:5: note: candidate: 'template<class _IteratorL, class _IteratorR> decltype ((__x.base() - __y.base())) std::operator-(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1778 |     operator-(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/12/bits/stl_iterator.h:1778:5: note:   template argument deduction/substitution failed:
/in/foo.cc:16:25: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'}
   16 |         cout<<s1.size()-a<<' '<<s2.size()-a0;
      |                         ^
/usr/include/c++/12/complex:362:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator-(const complex<_Tp>&, const complex<_Tp>&)'
  362 |     operator-(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/12/complex:362:5: note:   template argument deduction/substitution failed:
/in/foo.cc:16:25: note:   mismatched types 'const std::complex<_Tp>' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'}
   16 |         cout<<s1.size()-a<<' '<<s2.size()-a0;
      |                         ^
/usr/include/c++/12/complex:371:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator-(const complex<_Tp>&, const _Tp&)'
  371 |     operator-(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/include/c++/12/complex:371:5: note:   template argument deduction/substitution failed:
/in/foo.cc:16:25: note:   mismatched types 'const std::complex<_Tp>' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'}
   16 |         cout<<s1.size()-a<<' '<<s2.size()-a0;
      |                         ^
/usr/include/c++/12/complex:380:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator-(const _Tp&, const complex<_Tp>&)'
  380 |     operator-(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/12/complex:380:5: note:   template argument deduction/substitution failed:
/in/foo.cc:16:25: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::complex<_Tp>'
   16 |         cout<<s1.size()-a<<' '<<s2.size()-a0;
      |                         ^
/usr/include/c++/12/complex:457:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator-(const complex<_Tp>&)'
  457 |     operator-(const complex<_Tp>& __x)
      |     ^~~~~~~~
/usr/include/c++/12/complex:457:5: note:   template argument deduction/substitution failed:
/in/foo.cc:16:25: note:   mismatched types 'const std::complex<_Tp>' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'}
   16 |         cout<<s1.size()-a<<' '<<s2.size()-a0;
      |                         ^
In file included from /usr/include/c++/12/valarray:603,
                 from /usr/include/x86_64-linux-gnu/c++/12/bits/stdc++.h:95:
/usr/include/c++/12/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/12/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
/in/foo.cc:16:25: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'}
   16 |         cout<<s1.size()-a<<' '<<s2.size()-a0;
      |                         ^
/usr/include/c++/12/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/12/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
/in/foo.cc:16:25: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'}
   16 |         cout<<s1.size()-a<<' '<<s2.size()-a0;
      |                         ^
/usr/include/c++/12/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/12/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
/in/foo.cc:16:25: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   16 |         cout<<s1.size()-a<<' '<<s2.size()-a0;
      |                         ^
/usr/include/c++/12/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)