mpl.hpp

#pragma once
#include <ossia/detail/config.hpp>
 
#include <ossia/detail/for_each.hpp>
 
#include <brigand/algorithms/for_each.hpp>
#include <brigand/algorithms/transform.hpp>
#include <brigand/sequences/make_sequence.hpp>
 
#include <list>
#include <tuple>
#include <utility>
#include <vector>
 
namespace ossia
{
template <
    template <typename...> typename Sequence, template <typename...> typename Tuple,
    typename... Args>
auto list_of_tuple_to_tuple_of_list(const Sequence<Tuple<Args...>>& lst)
{
  namespace bg = brigand;
 
  // res_type = Tuple<Sequence<Arg1>, Sequence<Arg2>, ...>
  using res_type = bg::transform<Tuple<Args...>, bg::bind<Sequence, bg::_1>>;
 
  // list of integers over which we iterate
  using index_list = bg::make_sequence<bg::size_t<0>, sizeof...(Args)>;
 
  res_type res;
  // TODO reserve sizeof...(Args)
 
  // copy our data
  for(const auto& tuple : lst)
  {
    bg::for_each<index_list>([&](auto t) {
      constexpr auto N = decltype(t)::type::value;
      std::get<N>(res).push_back(std::get<N>(tuple));
    });
  }
  return res;
}
}