message: Fix return type of predicate_to_integral::operator()
diff: @@ -99,7 +99,7 @@ struct predicate_to_integral
  template <typename T>
  __host__ __device__
  - bool operator()(const T& x)
  + IntegralType operator()(const T& x)
  {
  return pred(x) ? IntegralType(1) : IntegralType(0);
  }
  