1 #pragma once
2
3 #include <petsc/private/cpp/macros.hpp> // PETSC_DECLTYPE_NOEXCEPT_AUTO_RETURNS
4 #include <petsc/private/cpp/utility.hpp> // index_sequence
5 #include <petsc/private/cpp/type_traits.hpp>
6
7 #include <array>
8
9 namespace Petsc
10 {
11
12 namespace util
13 {
14
15 namespace detail
16 {
17
18 template <class D, class...>
19 struct return_type_helper {
20 using type = D;
21 };
22
23 template <class... T>
24 struct return_type_helper<void, T...> : std::common_type<T...> { };
25
26 template <class D, class... T>
27 using array_return_type = std::array<typename return_type_helper<D, T...>::type, sizeof...(T)>;
28
29 template <typename T, std::size_t NL, std::size_t... IL, std::size_t NR, std::size_t... IR>
concat_array_impl(const std::array<T,NL> & l,const std::array<T,NR> & r,index_sequence<IL...>,index_sequence<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 }
34
35 } // namespace detail
36
37 template <class D = void, class... T>
make_array(T &&...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 }
42
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>{}))
45
46 } // namespace util
47
48 } // namespace Petsc
49