https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114841
--- Comment #2 from Matheus Izvekov <mizvekov at gmail dot com> --- I published https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p3310r0.html to address this problem, it has the most up-to-date wording. FYI the inconsistent deduction examples from problem #1 crash GCC.