foo.cc: In function 'int main()':
foo.cc:15:13: warning: comparison of constant '10' with boolean expression is always true [-Wbool-compare]
  else if(0<x<10)
          ~~~^~~
foo.cc:15:11: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
  else if(0<x<10)
          ~^~
foo.cc:19:14: warning: comparison of constant '25' with boolean expression is always true [-Wbool-compare]
  else if(10<x<25)
          ~~~~^~~
foo.cc:19:12: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
  else if(10<x<25)
          ~~^~
foo.cc:21:10: error: no match for 'operator^' (operand types are 'std::basic_ostream<char>' and 'int')
   cout<<x^2; 
   ~~~~~~~^~
foo.cc:21:10: note: candidate: operator^(int, int) <built-in>
foo.cc:21:10: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'int'
In file included from /usr/include/c++/7/ios:42:0,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from foo.cc:1:
/usr/include/c++/7/bits/ios_base.h:91:3: note: candidate: constexpr std::_Ios_Fmtflags std::operator^(std::_Ios_Fmtflags, std::_Ios_Fmtflags)
   operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
   ^~~~~~~~
/usr/include/c++/7/bits/ios_base.h:91:3: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'std::_Ios_Fmtflags'
/usr/include/c++/7/bits/ios_base.h:133:3: note: candidate: constexpr std::_Ios_Openmode std::operator^(std::_Ios_Openmode, std::_Ios_Openmode)
   operator^(_Ios_Openmode __a, _Ios_Openmode __b)
   ^~~~~~~~
/usr/include/c++/7/bits/ios_base.h:133:3: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'std::_Ios_Openmode'
/usr/include/c++/7/bits/ios_base.h:173:3: note: candidate: constexpr std::_Ios_Iostate std::operator^(std::_Ios_Iostate, std::_Ios_Iostate)
   operator^(_Ios_Iostate __a, _Ios_Iostate __b)
   ^~~~~~~~
/usr/include/c++/7/bits/ios_base.h:173:3: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'std::_Ios_Iostate'

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