feat(utils/member); add member_types

include/rebind/utils/member.hpp

@@ -20,6 +20,20 @@ namespace rebind::utils
 
     namespace impl
     {
+        template <typename T>
+        using member_types = decltype([]
+        {
+            constexpr auto arity = rebind::arity<T>;
+            using members        = decltype(rebind::members<T>);
+
+            constexpr auto unpack = []<auto... Is>(std::index_sequence<Is...>)
+            {
+                return std::type_identity<std::tuple<typename std::tuple_element_t<Is, members>::type...>>{};
+            };
+
+            return unpack(std::make_index_sequence<arity>());
+        }())::type;
+
         template <typename T>
         static constexpr auto member_names = []
         {
@@ -45,6 +59,10 @@ namespace rebind::utils
         }();
     } // namespace impl
 
+    template <typename T>
+        requires std::is_aggregate_v<T>
+    using member_types = impl::member_types<T>;
+
     template <typename T>
         requires std::is_aggregate_v<T>
     static constexpr auto member_names = impl::member_names<T>;

tests/member.test.cpp

@@ -37,9 +37,11 @@ suite<"member"> member_test = []
     expect(info.value == &simple::y);
 
     static constexpr auto members = rebind::members<simple>;
+    using member_types            = rebind::utils::member_types<simple>;
     static constexpr auto names   = rebind::utils::member_names<simple>;
 
     expect(std::tuple_size_v<decltype(members)> == 4);
+    expect(std::tuple_size_v<member_types> == 4);
     expect(names.size() == 4);
 
     expect(std::get<0>(members).name == "x");
@@ -59,6 +61,11 @@ suite<"member"> member_test = []
 
     expect(std::get<3>(members).index == 3);
 
+    expect(std::same_as<std::tuple_element_t<0, member_types>, int>);
+    expect(std::same_as<std::tuple_element_t<1, member_types>, float>);
+    expect(std::same_as<std::tuple_element_t<2, member_types>, double>);
+    expect(std::is_class_v<std::tuple_element_t<3, member_types>>);
+
     expect(std::same_as<std::tuple_element_t<0, decltype(members)>::type, int>);
     expect(std::same_as<std::tuple_element_t<1, decltype(members)>::type, float>);
     expect(std::same_as<std::tuple_element_t<2, decltype(members)>::type, double>);