From 84da4b5aa2fe1fa000ea20d571d0f3c9003f8f2b Mon Sep 17 00:00:00 2001
From: Sachi Sakurane <sakuranesachi@gmail.com>
Date: Thu, 26 Dec 2024 10:21:49 +0900
Subject: [PATCH] add tuple

---
 include/riw/tuple.hpp            |  3 +++
 include/riw/tuple/tuple_pair.hpp | 20 ++++++++++++++++++++
 2 files changed, 23 insertions(+)
 create mode 100644 include/riw/tuple.hpp
 create mode 100644 include/riw/tuple/tuple_pair.hpp

diff --git a/include/riw/tuple.hpp b/include/riw/tuple.hpp
new file mode 100644
index 0000000..65e9c1d
--- /dev/null
+++ b/include/riw/tuple.hpp
@@ -0,0 +1,3 @@
+#pragma once
+
+#include <riw/tuple/tuple_pair.hpp>
diff --git a/include/riw/tuple/tuple_pair.hpp b/include/riw/tuple/tuple_pair.hpp
new file mode 100644
index 0000000..27c1e71
--- /dev/null
+++ b/include/riw/tuple/tuple_pair.hpp
@@ -0,0 +1,20 @@
+#pragma once
+
+#include <tuple>
+#include <utility>
+
+namespace riw {
+namespace detail {
+  template <class... Ts, class... Us, std::size_t... Is>
+  constexpr inline auto tuple_pair_impl(const std::tuple<Ts...> &t1, const std::tuple<Us...> &t2,
+                                        std::index_sequence<Is...>) {
+    return std::make_tuple(std::make_pair(std::get<Is>(t1), std::get<Is>(t2))...);
+  }
+} // namespace detail
+
+template <class... Ts, class... Us>
+constexpr inline auto tuple_pair(const std::tuple<Ts...> &t1, const std::tuple<Us...> &t2) {
+  static_assert(sizeof...(Ts) == sizeof...(Us), "Tuples must have the same number of elements");
+  return detail::tuple_pair_impl(t1, t2, std::index_sequence_for<Ts...>{});
+}
+} // namespace riw