I am genuinely curious what's out-of-line mean here, especially comparing with Doxygen. Doxygen can generate xml output, and these xml output are easy to parse

I am genuinely curious what's out-of-line mean here, especially comparing with Doxygen. Doxygen can generate xml output, and these xml output are easy to parse to either generate markdown, or rst, and then feeding to to Jekyll or Sphinx.