1 files changed, 91 insertions, 4 deletions

diff --git a/source/blender/functions/FN_field_cpp_type.hh b/source/blender/functions/FN_field_cpp_type.hh
index 5e6f1b5a585..940faba6d70 100644
--- a/source/blender/functions/FN_field_cpp_type.hh
+++ b/source/blender/functions/FN_field_cpp_type.hh
@@ -30,19 +30,19 @@ template<typename T> struct FieldCPPTypeParam {
 
 class FieldCPPType : public CPPType {
  private:
-  const CPPType &field_type_;
+  const CPPType &base_type_;
 
  public:
   template<typename T>
   FieldCPPType(FieldCPPTypeParam<Field<T>> /* unused */, StringRef debug_name)
       : CPPType(CPPTypeParam<Field<T>, CPPTypeFlags::None>(), debug_name),
-        field_type_(CPPType::get<T>())
+        base_type_(CPPType::get<T>())
   {
   }
 
-  const CPPType &field_type() const
+  const CPPType &base_type() const
   {
-    return field_type_;
+    return base_type_;
   }
 
   /* Ensure that #GField and #Field<T> have the same layout, to enable casting between the two. */
@@ -60,6 +60,84 @@ class FieldCPPType : public CPPType {
   }
 };
 
+class ValueOrFieldCPPType : public CPPType {
+ private:
+  const CPPType &base_type_;
+  void (*construct_from_value_)(void *dst, const void *value);
+  void (*construct_from_field_)(void *dst, GField field);
+  const void *(*get_value_ptr_)(const void *value_or_field);
+  const GField *(*get_field_ptr_)(const void *value_or_field);
+  bool (*is_field_)(const void *value_or_field);
+  GField (*as_field_)(const void *value_or_field);
+
+ public:
+  template<typename T>
+  ValueOrFieldCPPType(FieldCPPTypeParam<ValueOrField<T>> /* unused */, StringRef debug_name)
+      : CPPType(CPPTypeParam<ValueOrField<T>, CPPTypeFlags::None>(), debug_name),
+        base_type_(CPPType::get<T>())
+  {
+    construct_from_value_ = [](void *dst, const void *value_or_field) {
+      new (dst) ValueOrField<T>(*(const T *)value_or_field);
+    };
+    construct_from_field_ = [](void *dst, GField field) {
+      new (dst) ValueOrField<T>(Field<T>(std::move(field)));
+    };
+    get_value_ptr_ = [](const void *value_or_field) {
+      return (const void *)&((ValueOrField<T> *)value_or_field)->value;
+    };
+    get_field_ptr_ = [](const void *value_or_field) -> const GField * {
+      return &((ValueOrField<T> *)value_or_field)->field;
+    };
+    is_field_ = [](const void *value_or_field) {
+      return ((ValueOrField<T> *)value_or_field)->is_field();
+    };
+    as_field_ = [](const void *value_or_field) -> GField {
+      return ((ValueOrField<T> *)value_or_field)->as_field();
+    };
+  }
+
+  const CPPType &base_type() const
+  {
+    return base_type_;
+  }
+
+  void construct_from_value(void *dst, const void *value) const
+  {
+    construct_from_value_(dst, value);
+  }
+
+  void construct_from_field(void *dst, GField field) const
+  {
+    construct_from_field_(dst, field);
+  }
+
+  const void *get_value_ptr(const void *value_or_field) const
+  {
+    return get_value_ptr_(value_or_field);
+  }
+
+  void *get_value_ptr(void *value_or_field) const
+  {
+    /* Use `const_cast` to avoid duplicating the callback for the non-const case. */
+    return const_cast<void *>(get_value_ptr_(value_or_field));
+  }
+
+  const GField *get_field_ptr(const void *value_or_field) const
+  {
+    return get_field_ptr_(value_or_field);
+  }
+
+  bool is_field(const void *value_or_field) const
+  {
+    return is_field_(value_or_field);
+  }
+
+  GField as_field(const void *value_or_field) const
+  {
+    return as_field_(value_or_field);
+  }
+};
+
 }  // namespace blender::fn
 
 #define MAKE_FIELD_CPP_TYPE(DEBUG_NAME, FIELD_TYPE) \
@@ -69,4 +147,13 @@ class FieldCPPType : public CPPType {
     static blender::fn::FieldCPPType cpp_type{ \
         blender::fn::FieldCPPTypeParam<blender::fn::Field<FIELD_TYPE>>(), STRINGIFY(DEBUG_NAME)}; \
     return cpp_type; \
+  } \
+  template<> \
+  const blender::fn::CPPType & \
+  blender::fn::CPPType::get_impl<blender::fn::ValueOrField<FIELD_TYPE>>() \
+  { \
+    static blender::fn::ValueOrFieldCPPType cpp_type{ \
+        blender::fn::FieldCPPTypeParam<blender::fn::ValueOrField<FIELD_TYPE>>(), \
+        STRINGIFY(DEBUG_NAME##OrValue)}; \
+    return cpp_type; \
   }