Libclang alternatives

• Doxygen
  • Most promising
  • clang assisted parsing is likely not needed / to slow
  • need to work out how to handle pp selectively
  • explore xml parsing options
• clang-doc
  • works, but cannot parse all TUs at once
  • Not sure if all the info is present
  • works with compile_commands.json
• castxml
  • no luck yet
• mrdocs
  • no luck yet
• https://github.com/robotpy/cxxheaderparser
  • looks promising