Geometry Nodes: deduplicate virtual array implementations

For some underlying data (e.g. spans) we had two virtual array
implementations. One for the mutable and one for the immutable
case. Now that most code does not deal with the virtual array
implementations directly anymore (since rBrBd4c868da9f97a),
we can get away with sharing one implementation for both cases.
This means that we have to do a `const_cast` in a few places, but
this is an implementation detail that does not leak into "user code"
(only when explicitly casting a `VArrayImpl` to a `VMutableArrayImpl`,
which should happen nowhere).

1 files changed, 3 insertions, 4 deletions

diff --git a/source/blender/blenkernel/intern/attribute_access.cc b/source/blender/blenkernel/intern/attribute_access.cc
index 3f2c1f13337..47ddb2494d0 100644
--- a/source/blender/blenkernel/intern/attribute_access.cc
+++ b/source/blender/blenkernel/intern/attribute_access.cc
@@ -50,7 +50,7 @@ using blender::bke::AttributeIDRef;
 using blender::bke::OutputAttribute;
 using blender::fn::GMutableSpan;
 using blender::fn::GSpan;
-using blender::fn::GVMutableArrayImpl_For_GMutableSpan;
+using blender::fn::GVArrayImpl_For_GSpan;
 
 namespace blender::bke {
 
@@ -1200,8 +1200,7 @@ blender::fn::GVArray GeometryComponent::attribute_get_for_read(const AttributeID
   return blender::fn::GVArray::ForSingle(*type, domain_size, default_value);
 }
 
-class GVMutableAttribute_For_OutputAttribute
-    : public blender::fn::GVMutableArrayImpl_For_GMutableSpan {
+class GVMutableAttribute_For_OutputAttribute : public blender::fn::GVArrayImpl_For_GSpan {
  public:
   GeometryComponent *component;
   std::string attribute_name;
@@ -1210,7 +1209,7 @@ class GVMutableAttribute_For_OutputAttribute
   GVMutableAttribute_For_OutputAttribute(GMutableSpan data,
                                          GeometryComponent &component,
                                          const AttributeIDRef &attribute_id)
-      : blender::fn::GVMutableArrayImpl_For_GMutableSpan(data), component(&component)
+      : blender::fn::GVArrayImpl_For_GSpan(data), component(&component)
   {
     if (attribute_id.is_named()) {
       this->attribute_name = attribute_id.name();