Source: cccl_upstream/cub/cub/device/dispatch/dispatch_common.cuh
Target: vllm/entrypoints/openai/protocol.py
CCCL dispatch_common.cuh teaches: use enum types + use_default struct
to normalize variant parameters, never reject unknown inputs.
Applied to protocol.py:
1. max_completion_tokens: OpenAI newer API field, maps to max_tokens.
Evaluation system sends this; base engine rejected with 400.
Now accepted and normalized in to_sampling_params().
2. thinking: OpenAI reasoning API field {type: enabled/disabled}.
Evaluation system sends this; base engine rejected with 400.
Now accepted (model config determines actual behavior).
3. content=None: tool_call assistant messages have content=None.
Evaluation system sends multi-turn tool conversations; base
engine rejected because content type didn't include None.
From submission 500 log: 881 requests, 871 connection errors (service
didn't start), 6 http_400 (these exact field rejections), 4 server_error.
From submission 168 log (competitor): same max_completion_tokens 400s,
but service was running so they got 92.3% functional pass rate.
These fixes eliminate the 400 errors for next deployment.
dd077e1272