works well, particularly after custom defining additional file type pairs with
(defvar my-cpp-other-file-alist '(("\\.cpp\\'" (".hpp" ".cuh"))
("\\.hpp\\'" (".cpp"".cu"))
("\\.cuh\\'" (".cu" ".cpp"))
("\\.cu\\'" (".cuh" ".hpp"))
("\\.c\\'" (".h"))
("\\.h\\'" (".c"))))
(setq-default ff-other-file-alist 'my-cpp-other-file-alist)
However, it does not switch files when point in on include directive in c/cpp files. What is the setting to always ignore the content under point in this context?