Add debug markers to react::value internal nodes to track their lifetime

libs/react/include/psemek/react/debug.hpp

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <psemek/react/value.hpp>
+
+namespace psemek::react
+{
+
+	template <typename T>
+	value<T> debug_marker(std::string marker, value<T> value)
+	{
+		value.node(detail::internal_tag{})->debug_marker = std::move(marker);
+		return value;
+	}
+
+}

libs/react/include/psemek/react/value.hpp

@@ -7,6 +7,7 @@
 #include <memory>
 #include <initializer_list>
 #include <type_traits>
+#include <string>
 
 namespace psemek::react
 {
@@ -20,6 +21,8 @@ namespace psemek::react
 		struct forever_tag
 		{};
 
+		void on_node_destroyed(std::string const & debug_marker);
+
 		template <typename T>
 		struct node
 		{
@@ -31,12 +34,19 @@ namespace psemek::react
 			std::optional<T> cached_value;
 			std::vector<std::shared_ptr<void>> subscriptions;
 
+			std::string debug_marker;
+
 			T const & value()
 			{
 				if (!cached_value)
 					cached_value.emplace(getter());
 				return *cached_value;
 			}
+
+			~node()
+			{
+				on_node_destroyed(debug_marker);
+			}
 		};
 
 		template <>
@@ -47,8 +57,15 @@ namespace psemek::react
 			util::signal<> internal_signal;
 			util::signal<> external_signal;
 
+			std::string debug_marker;
+
 			void value()
 			{}
+
+			~node()
+			{
+				on_node_destroyed(debug_marker);
+			}
 		};
 
 		template <typename T>
@@ -125,6 +142,11 @@ namespace psemek::react
 			return node_->internal_signal.subscribe(std::move(subscriber));
 		}
 
+		std::shared_ptr<detail::node<T>> node(detail::internal_tag)
+		{
+			return node_;
+		}
+
 	protected:
 		std::shared_ptr<detail::node<T>> node_;
 

libs/react/source/value.cpp

@@ -0,0 +1,18 @@
+#include <psemek/react/value.hpp>
+#include <psemek/util/unused.hpp>
+
+namespace psemek::react
+{
+
+	namespace detail
+	{
+
+		void on_node_destroyed(std::string const & debug_marker)
+		{
+			// Can put a breakpoint here to track destruction of specific nodes
+			unused(debug_marker);
+		}
+
+	}
+
+}