From 575af4c98031c9d0833394e118e7de7faf5573a3 Mon Sep 17 00:00:00 2001
From: Yonas Habteab <yonas.habteab@icinga.com>
Date: Tue, 8 Mar 2022 10:24:47 +0100
Subject: [PATCH] Defer: Allow to cancel the callback before going out of scope

---
 lib/base/defer.hpp | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/lib/base/defer.hpp b/lib/base/defer.hpp
index 9290c92b9..2a232619a 100644
--- a/lib/base/defer.hpp
+++ b/lib/base/defer.hpp
@@ -30,13 +30,21 @@ public:
 	inline
 	~Defer()
 	{
-		try {
-			m_Func();
-		} catch (...) {
-			// https://stackoverflow.com/questions/130117/throwing-exceptions-out-of-a-destructor
+		if (m_Func) {
+			try {
+				m_Func();
+			} catch (...) {
+				// https://stackoverflow.com/questions/130117/throwing-exceptions-out-of-a-destructor
+			}
 		}
 	}
 
+	inline
+	void Cancel()
+	{
+		m_Func = nullptr;
+	}
+
 private:
 	std::function<void()> m_Func;
 };