Set std::vector to a range

Question

What\'s the best way for setting an std::vector to a range, e.g. all numbers between 3 and 16?

Answer 1

std::iota - is useful, but it requires iterator, before creation vector, .... so I take own solution.

#include 
#include 

template struct seq{ typedef seq type;};

template< typename I, typename J> struct add;
template< int...I, int ...J>
struct add< seq, seq > : seq{};


template< int N>
struct make_seq : add< typename make_seq::type, 
                       typename make_seq::type > {};

template<> struct make_seq<0>{ typedef seq<> type; };
template<> struct make_seq<1>{ typedef seq<0> type; };


template
std::initializer_list range_impl(seq )
{
    return { (start + I*step) ...};
}

template
std::initializer_list range()
{ 
    return range_impl(typename make_seq< 1+ (finish - start )/step >::type {} ); 
}

int main()
{
    std::vector vrange { range<3, 16>( )} ;

    for(auto x : vrange)std::cout << x << ' ';

}


Output:

  3 4 5 6 7 8 9 10 11 12 13 14 15 16