C++ make_array

make_array.hpp

#include <array>
#include <tuple>
#include <utility>

/*
  Makes a std::array of objects without a default constructor.
  C++17 is required for std::make_from_tuple, otherwise can be adapted for C++14.
  Example usage:
  struct A {
    A(std::string s) {}
  };
  std::array<A, 12> arr = make_array<A, 12>("abc");
*/

template <typename T, typename ArgT, std::size_t... Is>
constexpr std::array<T, sizeof...(Is)> make_array_impl(ArgT&& argt, std::index_sequence<Is...>) {
  return {{(Is, std::make_from_tuple<T>(std::forward<ArgT>(argt)))...}};
}

template <typename T, std::size_t N, typename... Args>
constexpr std::array<T, N> make_array(Args&&... args) {
  return make_array_impl<T>(std::make_tuple(std::forward<Args>(args)...), std::make_index_sequence<N>());
}