template<class T>
valarray<T> operator^(const valarray<T>& lhs,
const valarray<T>& rhs);
template<class T>
valarray<T> operator^(const valarray<T> lhs, const T& rhs);
template<class T>
valarray<T> operator^(const T& lhs, const valarray<T>& rhs);The first template operator returns an object of class valarray<T>, each of whose elements I is x[I] ^ y[I]. The
second template operator stores in element I x[I] ^ y. The third template operator stores in element I x ^ y[I].