Function shuffle_array

crawl-ref/source/random.h:272–281

// I must be a random-access iterator.
template <typename I>
void shuffle_array(I begin, I end)
{
    size_t n = end - begin;
    while (n > 1)
    {
        const int i = random2(n);
        n--;
        iter_swap(begin + i, begin + n);
    }
}

template <typename T>
void shuffle_array(T &vec)