On Mon, 22 May 2023, Jonathan Wakely via Libstdc++ wrote:
* subscripting vector builtins is not allowed in constant expressionsIs that just because nobody made it work (yet)?
Yes. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101651 and others.
* if the implementation would otherwise call SIMD intrinsics/builtins
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80517 and others. Makes sense to work around them for now. -- Marc Glisse