Define a preprocessor flag for enabling warnings on unused Connection…

…Handle

src/kdbindings/signal.h

@@ -11,6 +11,11 @@
 
 #pragma once
 
+// Enables compiler warnings for unused ConnectionHandle results.
+#ifndef KDBINDINGS_WARN_UNUSED
+#define KDBINDINGS_WARN_UNUSED [[nodiscard]]
+#endif
+
 #include <assert.h>
 #include <memory>
 #include <stdexcept>
@@ -253,7 +258,7 @@ class Signal
      * @return An instance of ConnectionHandle, that can be used to disconnect
      * or temporarily block the connection.
      */
-    ConnectionHandle connect(std::function<void(Args...)> const &slot)
+    KDBINDINGS_WARN_UNUSED ConnectionHandle connect(std::function<void(Args...)> const &slot)
     {
         ensureImpl();
 
@@ -278,7 +283,7 @@ class Signal
      * The Signal class itself is not thread-safe. While the ConnectionEvaluator is inherently
      * thread-safe, ensure that any concurrent access to this Signal is protected externally to maintain thread safety.
      */
-    ConnectionHandle connectDeferred(const std::shared_ptr<ConnectionEvaluator> &evaluator, std::function<void(Args...)> const &slot)
+    KDBINDINGS_WARN_UNUSED ConnectionHandle connectDeferred(const std::shared_ptr<ConnectionEvaluator> &evaluator, std::function<void(Args...)> const &slot)
     {
         ensureImpl();