https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91222
--- Comment #16 from Martin Liška <marxin at gcc dot gnu.org> --- (In reply to Jason Merrill from comment #15) > (In reply to Jason Merrill from comment #13) > > But that still doesn't make the types the same, and the use of the variable > > in 2.ii has undefined behavior because it is accessing the value of the > > object through the wrong type, so the warning is correct. We may want to > > allow it anyway for C compatibility. Thoughts? > > This does seem like significant trouble to make something work that isn't > actually valid C++, and it isn't hard to fix the code by giving the struct a > name. Is the problematic header part of publicly available source code or > only the benchmark? I've just done rebuild of openSUSE:Factory with current gcc10 master and I see it only in one package: aegisub. So I would consider it very rare.