[Bug c++/91780] Discrepancy between gcc 7.4, through 9.2, compared to clang.

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91780

--- Comment #11 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Can't you just change your constructor to this?

    zip(Containers&&... containers) :
containers_(std::forward<Containers>(containers)...) { }


The problematic deduction seems to only happen because of the odd constructor
with an unused parameter pack that gets deduced as empty.