/in/foo.cc: In function 'bool hw(int)':
/in/foo.cc:12:3: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
  y/=10;
  ~^~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:12:3: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
  y/=10;
  ~^~~~
/in/foo.cc:5:6: note: 'y' was declared here
  int y,t=x;
      ^