1: #pragma once

  3: #include <petsc/private/cpp/macros.hpp>
  4: #include <petsc/private/cpp/utility.hpp>
  5: #include <petsc/private/cpp/type_traits.hpp>

  7: #include <array>

  9: namespace Petsc
 10: {

 12: namespace util
 13: {

 15: namespace detail
 16: {

 18: template <class D, class...>
 19: struct return_type_helper {
 20:   using type = D;
 21: };

 23: template <class... T>
 24: struct return_type_helper<void, T...> : std::common_type<T...> { };

 26: template <class D, class... T>
 27: using array_return_type = std::array<typename return_type_helper<D, T...>::type, sizeof...(T)>;

 29: template <typename T, std::size_t NL, std::size_t... IL, std::size_t NR, std::size_t... IR>
 30: inline constexpr std::array<T, NL + NR> concat_array_impl(const std::array<T, NL> &l, const std::array<T, NR> &r, index_sequence<IL...>, index_sequence<IR...>) noexcept(std::is_nothrow_copy_constructible<T>::value)
 31: {
 32:   return {l[IL]..., r[IR]...};
 33: }

 35: } // namespace detail

 37: template <class D = void, class... T>
 38: PETSC_NODISCARD inline constexpr detail::array_return_type<D, T...> make_array(T &&...t) noexcept(std::is_nothrow_constructible<detail::array_return_type<D, T...>>::value)
 39: {
 40:   return {std::forward<T>(t)...};
 41: }

 43: template <typename T, std::size_t NL, std::size_t NR>
 44: PETSC_NODISCARD inline constexpr auto concat_array(const std::array<T, NL> &l, const std::array<T, NR> &r) PETSC_DECLTYPE_NOEXCEPT_AUTO_RETURNS(detail::concat_array_impl(l, r, make_index_sequence<NL>{}, make_index_sequence<NR>{}))

 46: } // namespace util

 48: } // namespace Petsc