/in/foo.cc: In function 'long double qp(long double, long double)':
/in/foo.cc:9:6: error: invalid operands of types 'long double' and 'int' to binary 'operator&'
  if(b&1)return qp(a,b/2)*qp(a,b/2)*a;
     ~^~
/in/foo.cc:11:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^