message: Allow tables that are entirely composed of native inlines to be copied.
diff: @@ -1299,7 +1299,8 @@ class CppGenerator : public BaseGenerator {
  for (auto fit = ev.union_type.struct_def->fields.vec.begin();
  fit != ev.union_type.struct_def->fields.vec.end(); ++fit) {
  const auto &field = **fit;
  - if (!field.deprecated && field.value.type.struct_def) {
  + if (!field.deprecated && field.value.type.struct_def &&
  + !field.native_inline) {
  copyable = false;
  break;
  }
  