https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61312
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- http://www.dansaks.com/articles/2000-02%20Top-Level%20cv-Qualifiers%20in%20Function%20Parameters.pdf
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61312
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- http://www.dansaks.com/articles/2000-02%20Top-Level%20cv-Qualifiers%20in%20Function%20Parameters.pdf