From dba080715258700aa657834dc0af3a351a62751b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jean-Micha=C3=ABl=20Celerier?=
 <jeanmichael.celerier@gmail.com>
Date: Sat, 6 Apr 2024 12:15:15 -0400
Subject: [PATCH] [avnd] Add a function to iterate fields with their index

---
 include/avnd/common/struct_reflection.hpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/include/avnd/common/struct_reflection.hpp b/include/avnd/common/struct_reflection.hpp
index 884b9c9c..050c53a2 100644
--- a/include/avnd/common/struct_reflection.hpp
+++ b/include/avnd/common/struct_reflection.hpp
@@ -71,6 +71,21 @@ struct fields_introspection
 #endif
   }
 
+  template <typename F>
+  static constexpr void for_all_n(type& fields, F&& func) noexcept
+  {
+#if AVND_USE_BOOST_PFR
+    if constexpr(size > 0)
+    {
+      avnd::for_each_field_ref_n(fields, std::forward<F>(func));
+    }
+#else
+    // FIXME pass it the avnd::field_index<I>
+    auto&& [... elts] = fields;
+    (func(elts), ...);
+#endif
+  }
+
   static constexpr void for_nth(type& fields, int n, auto&& func) noexcept
   {
     // TODO maybe there is some dirty hack to do here with offsetof computations...