/in/foo.cc: In function 'bool hw(int)':
/in/foo.cc:12:2: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if(a==b)
  ^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:6:10: warning: 'b' is used uninitialized in this function [-Wuninitialized]
  int a=x,b;
          ^