This one took me a while to grasp. Kept trying to unpack the variadic parameter using recursive calls to reversed_binary_value(). But once I understood the problem better, I was able to solve it.

Without giving too much away, here's what I did:

template <bool ...digits>
int reversed_binary_value()
{
    const size_t size = sizeof...(digits);
    bool bits[size] = { digits... };
    
    // reverse order of array
    
    // convert bit array into integer number
    
    // return number
}

If anyone knows of a more appropriate way of solving this challenge, please let me know.