[Bug libstdc++/109203] sort(zip(v1, v2)) fails to compile

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109203

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Technically, that's needed for libstdc++ too, it just happens to work "by
accident" without it.