From f3fadb63b662b63d19f5d3cafe7b474b5eb68540 Mon Sep 17 00:00:00 2001
From: Sai Kishor Kothakota <sai.kishor@pal-robotics.com>
Date: Fri, 14 Feb 2025 17:45:20 +0100
Subject: [PATCH] fix introspection for handles with variable references

---
 .../include/hardware_interface/handle.hpp            | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/hardware_interface/include/hardware_interface/handle.hpp b/hardware_interface/include/hardware_interface/handle.hpp
index ddb9dbd99c..ccb4e29f17 100644
--- a/hardware_interface/include/hardware_interface/handle.hpp
+++ b/hardware_interface/include/hardware_interface/handle.hpp
@@ -206,17 +206,17 @@ class StateInterface : public Handle
 
   void registerIntrospection() const
   {
-    if (std::holds_alternative<double>(value_))
+    if (value_ptr_ || std::holds_alternative<double>(value_))
     {
       std::function<double()> f = [this]()
-      { return value_ptr_ ? *value_ptr_ : std::numeric_limits<double>::quiet_NaN(); };
+      { return value_ptr_ ? *value_ptr_ : std::get<double>(value_); };
       DEFAULT_REGISTER_ROS2_CONTROL_INTROSPECTION("state_interface." + get_name(), f);
     }
   }
 
   void unregisterIntrospection() const
   {
-    if (std::holds_alternative<double>(value_))
+    if (value_ptr_ || std::holds_alternative<double>(value_))
     {
       DEFAULT_UNREGISTER_ROS2_CONTROL_INTROSPECTION("state_interface." + get_name());
     }
@@ -251,17 +251,17 @@ class CommandInterface : public Handle
 
   void registerIntrospection() const
   {
-    if (std::holds_alternative<double>(value_))
+    if (value_ptr_ || std::holds_alternative<double>(value_))
     {
       std::function<double()> f = [this]()
-      { return value_ptr_ ? *value_ptr_ : std::numeric_limits<double>::quiet_NaN(); };
+      { return value_ptr_ ? *value_ptr_ : std::get<double>(value_); };
       DEFAULT_REGISTER_ROS2_CONTROL_INTROSPECTION("command_interface." + get_name(), f);
     }
   }
 
   void unregisterIntrospection() const
   {
-    if (std::holds_alternative<double>(value_))
+    if (value_ptr_ || std::holds_alternative<double>(value_))
     {
       DEFAULT_UNREGISTER_ROS2_CONTROL_INTROSPECTION("command_interface." + get_name());
     }