Cleanup: add forward declaration header for IndexMask and VArray

This avoids duplicating the declaration in multiple places.

source/blender/blenkernel/BKE_instances.hh

@@ -24,6 +24,7 @@
 
 #include "BLI_array.hh"
 #include "BLI_function_ref.hh"
+#include "BLI_index_mask_fwd.hh"
 #include "BLI_math_matrix_types.hh"
 #include "BLI_vector.hh"
 
@@ -31,17 +32,11 @@
 
 struct Object;
 struct Collection;
-namespace blender {
-namespace index_mask {
-class IndexMask;
-}
-using index_mask::IndexMask;
-namespace bke {
+namespace blender::bke {
 class AnonymousAttributePropagationInfo;
 class AttributeAccessor;
 class MutableAttributeAccessor;
-}  // namespace bke
-}  // namespace blender
+}  // namespace blender::bke
 
 namespace blender::bke {
 

source/blender/blenkernel/BKE_mesh.hh

@@ -8,13 +8,7 @@
  * \ingroup bke
  */
 
-namespace blender {
-namespace index_mask {
-class IndexMask;
-}
-using index_mask::IndexMask;
-}  // namespace blender
-
+#include "BLI_index_mask_fwd.hh"
 #include "BLI_offset_indices.hh"
 
 #include "BKE_mesh.h"

source/blender/blenkernel/BKE_subdiv_ccg.hh

@@ -10,15 +10,9 @@
 
 #include <memory>
 
-namespace blender {
-namespace index_mask {
-class IndexMask;
-}
-using index_mask::IndexMask;
-}  // namespace blender
-
 #include "BLI_array.hh"
 #include "BLI_bit_group_vector.hh"
+#include "BLI_index_mask_fwd.hh"
 #include "BLI_offset_indices.hh"
 #include "BLI_sys_types.h"
 

source/blender/blenlib/BLI_index_mask.hh

@@ -11,15 +11,13 @@
 
 #include "BLI_bit_span.hh"
 #include "BLI_function_ref.hh"
+#include "BLI_index_mask_fwd.hh"
 #include "BLI_linear_allocator.hh"
 #include "BLI_offset_span.hh"
 #include "BLI_task.hh"
 #include "BLI_unique_sorted_indices.hh"
 #include "BLI_vector.hh"
-
-namespace blender {
-template<typename T> class VArray;
-}
+#include "BLI_virtual_array_fwd.hh"
 
 namespace blender::index_mask {
 

source/blender/blenlib/BLI_index_mask_fwd.hh

@@ -0,0 +1,17 @@
+/* SPDX-FileCopyrightText: 2024 Blender Authors
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+
+namespace blender::index_mask {
+
+class IndexMask;
+
+}  // namespace blender::index_mask
+
+namespace blender {
+
+using index_mask::IndexMask;
+
+}  // namespace blender

source/blender/blenlib/BLI_offset_indices.hh

@@ -6,13 +6,7 @@
 
 #include <algorithm>
 
-namespace blender {
-namespace index_mask {
-class IndexMask;
-}
-using index_mask::IndexMask;
-}  // namespace blender
-
+#include "BLI_index_mask_fwd.hh"
 #include "BLI_index_range.hh"
 #include "BLI_span.hh"
 

source/blender/blenlib/BLI_virtual_array_fwd.hh

@@ -0,0 +1,12 @@
+/* SPDX-FileCopyrightText: 2024 Blender Authors
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+
+namespace blender {
+
+template<typename T> class VArray;
+template<typename T> class VMutableArray;
+
+}  // namespace blender

source/blender/blenlib/CMakeLists.txt

@@ -251,6 +251,7 @@ set(SRC
   BLI_implicit_sharing.hh
   BLI_implicit_sharing_ptr.hh
   BLI_index_mask.hh
+  BLI_index_mask_fwd.hh
   BLI_index_range.hh
   BLI_inplace_priority_queue.hh
   BLI_iterator.h
@@ -380,6 +381,7 @@ set(SRC
   BLI_vector_set.hh
   BLI_vector_set_slots.hh
   BLI_virtual_array.hh
+  BLI_virtual_array_fwd.hh
   BLI_virtual_vector_array.hh
   BLI_voxel.h
   BLI_winstuff.h