https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111299
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Jiang An from comment #1) > > What ends up happening is that in order to bind x.value to the reference > > parameter R&& r, we can't actually do that, so instead we create a > > temporary initialized by copying x.value and we bind a reference to that > > temporary, returning a Span pointing to... that. > > This looks like miscompilation. [[gnu::packed]] should have no effect here. > > Clang seemingly correctly compiles the function > (https://godbolt.org/z/7x8fGcEM9). No, [[gnu::packed]] means you cannot bind a full reference to an element of that struct because it would be miscompiled. clang actually miscompiles this because then the alignment for the refernece would be incorrect ...
