add KDBINDINGS_ENABLE_WARN_UNUSED as a cmake option

cmake/KDBindingsConfig.h.in

@@ -0,0 +1,10 @@
+#pragma once
+
+// Check if KDBINDINGS_ENABLE_WARN_UNUSED option is set
+#cmakedefine KDBINDINGS_ENABLE_WARN_UNUSED
+
+#ifdef KDBINDINGS_ENABLE_WARN_UNUSED
+#define KDBINDINGS_WARN_UNUSED [[nodiscard]]
+#else
+#define KDBINDINGS_WARN_UNUSED
+#endif

src/kdbindings/CMakeLists.txt

@@ -6,6 +6,13 @@
 # Contact KDAB at <info@kdab.com> for commercial licensing options.
 #
 
+option(KDBINDINGS_ENABLE_WARN_UNUSED "Enable warnings for unused ConnectionHandles" OFF)
+
+configure_file(
+    "${PROJECT_SOURCE_DIR}/cmake/KDBindingsConfig.h.in"
+    "${CMAKE_BINARY_DIR}/include/KDBindingsConfig.h"
+)
+
 set(HEADERS
     binding.h
     binding_evaluator.h
@@ -36,6 +43,7 @@ set_target_properties(KDBindings PROPERTIES
 target_include_directories(KDBindings INTERFACE
   $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/..>
   $<INSTALL_INTERFACE:include>
+  $<BUILD_INTERFACE:${CMAKE_BINARY_DIR}/include>  # Include the build directory for the configured header
 )
 if(KDBindings_ERROR_ON_WARNING)
   if(MSVC)

src/kdbindings/signal.h

@@ -11,11 +11,6 @@
 
 #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>
@@ -26,6 +21,8 @@
 #include <kdbindings/genindex_array.h>
 #include <kdbindings/utils.h>
 
+#include <KDBindingsConfig.h>
+
 /**
  * @brief The main namespace of the KDBindings library.
  *