Cleanup: move C++ declarations to separate .hh header

source/blender/editors/include/ED_node.h

@@ -176,20 +176,3 @@ bool ED_space_node_color_sample(struct Main *bmain,
 #ifdef __cplusplus
 }
 #endif
-
-#ifdef __cplusplus
-
-/* node_relationships.cc */
-
-namespace blender::ed::space_node {
-
-void node_insert_on_link_flags_set(SpaceNode &snode, const ARegion &region);
-/**
- * Assumes link with #NODE_LINKFLAG_HILITE set.
- */
-void node_insert_on_link_flags(Main &bmain, SpaceNode &snode);
-void node_insert_on_link_flags_clear(bNodeTree &node_tree);
-
-}  // namespace blender::ed::space_node
-
-#endif

source/blender/editors/include/ED_node.hh

@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+
+#include "ED_node.h"
+
+struct SpaceNode;
+struct ARegion;
+struct Main;
+struct bNodeTree;
+
+namespace blender::ed::space_node {
+
+void node_insert_on_link_flags_set(SpaceNode &snode, const ARegion &region);
+
+/**
+ * Assumes link with #NODE_LINKFLAG_HILITE set.
+ */
+void node_insert_on_link_flags(Main &bmain, SpaceNode &snode);
+void node_insert_on_link_flags_clear(bNodeTree &node_tree);
+
+}  // namespace blender::ed::space_node

source/blender/editors/space_node/node_relationships.cc

@@ -23,7 +23,7 @@
 #include "BKE_node_tree_update.h"
 #include "BKE_screen.h"
 
-#include "ED_node.h" /* own include */
+#include "ED_node.hh" /* own include */
 #include "ED_render.h"
 #include "ED_screen.h"
 #include "ED_space_api.h"

source/blender/editors/transform/transform_convert_node.cc

@@ -18,7 +18,7 @@
 #include "BKE_node_tree_update.h"
 #include "BKE_report.h"
 
-#include "ED_node.h"
+#include "ED_node.hh"
 
 #include "UI_interface.h"
 #include "UI_view2d.h"