/in/foo.cc: In function 'void update(int, int)':
/in/foo.cc:71:8: warning: unused variable 'fleft' [-Wunused-variable]
   bool fleft=0,fright=0;
        ^~~~~
/in/foo.cc:71:16: warning: unused variable 'fright' [-Wunused-variable]
   bool fleft=0,fright=0;
                ^~~~~~