https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102609
--- Comment #30 from Gašper Ažman <gasper.azman at gmail dot com> --- I don't really understand what you meant by "they have corresponding object parameters" - you mean that the object parameters are equal in both constraint and type? "Corresponding" to my recollection is only used for argument-to-parameter correspondence, but I could be wrong.