[Bug libstdc++/85771] `std::variant<...>` insanely slow to compile compared to `union` (256 types)

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85771

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This should be completely unsurprising, obviously std::variant is different to
a union. The type safety and other features come at a cost, and 2s isn't
insane.