foo.cc: In function 'int main()':
foo.cc:11:10: warning: comparison of constant '10' with boolean expression is always true [-Wbool-compare]
   11 |   if(1<=x<10){
      |      ~~~~^~~
foo.cc:11:7: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
   11 |   if(1<=x<10){
      |      ~^~~
foo.cc:16:12: warning: comparison of constant '15' with boolean expression is always true [-Wbool-compare]
   16 |    if(10<=x<15){
      |       ~~~~~^~~
foo.cc:16:9: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
   16 |    if(10<=x<15){
      |       ~~^~~
foo.cc:21:13: warning: comparison of constant '30' with boolean expression is always true [-Wbool-compare]
   21 |     if(15<=x<30){
      |        ~~~~~^~~
foo.cc:21:10: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
   21 |     if(15<=x<30){
      |        ~~^~~

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