operator&

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].