foo.cc: In function 'int main()':
foo.cc:11:9: warning: comparison of constant '10' with boolean expression is always true [-Wbool-compare]
   11 |  if(1<=x<10)
      |     ~~~~^~~
foo.cc:11:6: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
   11 |  if(1<=x<10)
      |     ~^~~
foo.cc:13:10: warning: comparison of constant '15' with boolean expression is always true [-Wbool-compare]
   13 |  if(10<=x<15)
      |     ~~~~~^~~
foo.cc:13:7: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
   13 |  if(10<=x<15)
      |     ~~^~~
foo.cc:15:10: warning: comparison of constant '30' with boolean expression is always true [-Wbool-compare]
   15 |  if(15<=x<30)
      |     ~~~~~^~~
foo.cc:15:7: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
   15 |  if(15<=x<30)
      |     ~~^~~
foo.cc:7:11: warning: variable 'y' set but not used [-Wunused-but-set-variable]
    7 |     int x,y;
      |           ^

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