Thanks, but I do not see the relevance of that article. I would like to construct a loop in a Graph from the five elementary operations, while the linked article does not even mention them.
I also might be in the dark regarding versions, but my understanding is that new TF2 features like while_loop actually generate under the hood the same old elementary operations that are used in TF1. Maybe the terminology I used was incorrect, but the emphasis is to build the Graph from elementary operations.
Also, the link is around Python code, while I want to use a more direct access. Actually I work on a Pascal wrapper around the C calls. So I could simplify my question, how to make a while loop using the C API. Actually I did not even find a C++ solution. For TF2 C++ API the control_flow_ops still contain only the elementary operations.
Yet another approach to the same question: I can use the 800+ operations ops.pbtxt. Those include the 5 mentioned ops, but not while_loop. Maybe the elementary while could be used somehow?