Fix variant visitation
So, as it turns out, pacxx supports c++17 on agamemnon, probably due to Ubuntu
18.04 (compared to Ubuntu 16.04 in the CI). This means Dune::Std::variant
is just std::variant
, rather than using Dune's fallback implementation.
Now, with the fallback implementation, it was impossible to find visit()
via
ADL for some reason, so I had been using the member function visit()
, which
isn't part of std::variant
. To satisfy both, try using Dune::Std::visit
before ADL.