pow

template<class T>
    valarray<T> pow(const valarray<T>& x,
        const valarray<T>& y);
template<class T>
    valarray<T> pow(const valarray<T> x, const T& y);
template<class T>
    valarray<T> pow(const T& x, const valarray<T>& y);

The first template function returns an object of class valarray<T>, each of whose elements I is x[I] raised to the y[I] power. The second template function stores in element I x[I] raised to the y power. The third template function stores in element I x raised to the y[I] power.