[BUG] [cpp-qt-client] C++ compiler error "'asJsonObject': is not a member of" when pulling enums into schemas

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
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Description

When I pull the pet status enum in the modules/openapi-generator/src/test/resources/3_0/petstore.json file into the schemas section of the .json file and use the schema in the /pet/findByStatus function and then compile the generated library I get the follwing compiler error:

client\PFXPetApi.cpp(499,48): error C2039: 'asJsonObject': is not a member of 'test_namespace::PFXPetStatus'

The created class PFXPetStatus derives from PFXEnum. Neither provides a asJsonObject() function.

openapi-generator version

7.8.0-20240702.091835-1

OpenAPI declaration file content or url

Here ist the modified petstore.json that reproduces the problem

https://gist.github.com/Knitschi/9c86f1e06dd52c29ee4cdb79ce540fa7

The difference to the original file is that it introduces a schema with the PetStatus enum that is then used in the definition of the /pet/findByStatus function and the Pet schema.

Generation Details

Client was generated with

java -jar openapi-generator-cli-7.8.0-20240702.091835-1.jar generate --input-spec petstore.json --generator-name cpp-qt-client --output . --package-name CppQtPetstoreClient --additional-properties cppNamespace=test_namespace --minimal-update --model-name-prefix PFX 

Steps to reproduce

• Generate and compile the example samples\client\petstore\cpp-qt with the modified petstore.json file.

Possible Fix

I am not competent enough to provide one.

Related issues/PRs

Maybe this issue is related to: https://github.com/OpenAPITools/openapi-generator/issues/15277

Start with the modified petstore.json from the issue and generate samples/client/petstore/cpp-qt using the cpp-qt-client generator. Trace the generated PFXPetStatus type and the call in client/PFXPetApi.cpp that produces the asJsonObject error. Done means the generated library compiles when the PetStatus enum is pulled into schemas and used by /pet/findByStatus.