Tuple to parameter pack

Question

This below code from user Faheem Mitha, is based on user Johannes Schaub - litb\'s answer in this SO. This code perfectly does what I seek, which is conversion of a tu

Answer 1

With C++17 you can use "if constexpr" to create a sequence wrapper:

template  class spack, int ... seq>
constexpr auto get_seq17()
{
    static_assert(indxMax >= 0, "Sequence size must be equal to or greater than 0!");
    if constexpr (indxMax > 0)
    {
        typedef decltype(spack{}) frst;
        constexpr int next = indxMax - 1;
        return get_seq17();
    }
    else
    {
        return spack{};
    }
}

template  class pack>
struct seq_pack
{
    typedef decltype(get_seq17()) seq;
};


//creating a sequence wrapper
template 
struct seqpack {};

//usage
seq_pack<4, seqpack>::seq; //seqpack<0, 1, 2, 3, 4> 

Though this implementation is easier to understand, it is preferable to use std::make_index_sequence as Julius has mentioned in the comments below.