https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96533
Nathaniel Shead <natattak at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|ICE with -Wunused-parameter |ICE with three-way |when using three-way |comparison when error |comparison |occurs in templated | |operator< overload --- Comment #2 from Nathaniel Shead <natattak at gmail dot com> --- (Correction with my previous comment, apologies; should be struct S {}; auto operator<=>(S, S) { return std::strong_ordering::equal; } — see https://godbolt.org/z/aPxv8d, or otherwise a friend as in my first post.)