foo.cc: In function 'int main()':
foo.cc:19:12: warning: comparison of constant '15' with boolean expression is always true [-Wbool-compare]
   19 |    if(10<=x<15)
      |       ~~~~~^~~
foo.cc:19:9: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
   19 |    if(10<=x<15)
      |       ~~^~~
foo.cc:25:13: warning: comparison of constant '30' with boolean expression is always true [-Wbool-compare]
   25 |     if(15<=x<30)
      |        ~~~~~^~~
foo.cc:25:10: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
   25 |     if(15<=x<30)
      |        ~~^~~
foo.cc:5:8: warning: unused variable 'y' [-Wunused-variable]
    5 |  int x,y;
      |        ^

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