From 0029f2027a6c8646fb61a09b1791f49bdae6b931 Mon Sep 17 00:00:00 2001
From: qicosmos <qicosmos@linux.alibaba.com>
Date: Wed, 11 Dec 2024 11:26:46 +0800
Subject: [PATCH] [reflection][feat]Add index of (#851)

---
 include/ylt/reflection/member_value.hpp  |  7 +++++++
 src/reflection/tests/test_reflection.cpp | 18 ++++++++++++++----
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/include/ylt/reflection/member_value.hpp b/include/ylt/reflection/member_value.hpp
index afa307a1a..3ed76b942 100644
--- a/include/ylt/reflection/member_value.hpp
+++ b/include/ylt/reflection/member_value.hpp
@@ -176,6 +176,13 @@ inline size_t index_of(T& t, Field& value) {
   return std::distance(offset_arr.begin(), it);
 }
 
+template <typename Member>
+inline size_t index_of(Member member) {
+  using T = typename member_traits<Member>::owner_type;
+  static auto& t = internal::get_fake_object<T>();
+  return index_of(t, t.*member);
+}
+
 template <typename T, typename Field>
 inline constexpr std::string_view name_of(T& t, Field& value) {
   size_t index = index_of(t, value);
diff --git a/src/reflection/tests/test_reflection.cpp b/src/reflection/tests/test_reflection.cpp
index ae9cbad11..6cd0774c4 100644
--- a/src/reflection/tests/test_reflection.cpp
+++ b/src/reflection/tests/test_reflection.cpp
@@ -313,6 +313,16 @@ TEST_CASE("test macros") {
   constexpr size_t size = members_count_v<dummy_t>;
   static_assert(size == 3);
 
+  constexpr auto idx = index_of<&simple2::age>();
+  static_assert(idx == 3);
+  constexpr auto idx2 = index_of<&simple2::id>();
+  static_assert(idx2 == 1);
+
+  auto i = index_of(&simple::id);
+  CHECK(i == 1);
+  i = index_of(&simple::age);
+  CHECK(i == 3);
+
   auto ref_tp = object_to_tuple(t);
   auto& c = std::get<0>(ref_tp);
   c = 10;
@@ -366,11 +376,11 @@ TEST_CASE("test macros") {
   auto& var1 = get<"str">(t);
   CHECK(var1 == "hello reflection");
 
-  constexpr size_t idx = index_of<simple2, "str">();
-  CHECK(idx == 2);
+  constexpr size_t i3 = index_of<simple2, "str">();
+  CHECK(i3 == 2);
 
-  constexpr size_t idx2 = index_of<simple2, "no_such">();
-  CHECK(idx2 == 4);
+  constexpr size_t i4 = index_of<simple2, "no_such">();
+  CHECK(i4 == 4);
 #endif
 
   constexpr std::string_view name1 = name_of<simple2, 2>();