From ec004393b9c0c4d364d3787f07c5e5e96e31935d Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Mon, 16 Feb 2026 11:03:36 -0500
Subject: [PATCH] xo-reader2: enable alloc headers for parser stack

---
 include/xo/arena/AllocHeader.hpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/xo/arena/AllocHeader.hpp b/include/xo/arena/AllocHeader.hpp
index ec99f59..db8b678 100644
--- a/include/xo/arena/AllocHeader.hpp
+++ b/include/xo/arena/AllocHeader.hpp
@@ -11,6 +11,13 @@
 
 namespace xo {
     namespace mm {
+        /** @brief per-alloc header
+         *
+         *  Appears immediately before each allocation when
+         *  ArenaConfig.store_header_flag_ is set.
+         *
+         *  See AllocInfo.hpp for encoding of @ref repr_
+         **/
         struct AllocHeader {
             using repr_type = std::uintptr_t;
             using size_type = std::size_t;