since updating to ecc 5.2.0, problems with std::variant<>: using it results in the error: error: no template named 'variant' in namespace 'std'. In fact, all c++17 feature are unusable. ecc is ...
I don't get the whole SuggestionStage thing. Comments say it's to help speed things up and be more memory efficient, but looking at the code I can't see how it would do anything but the opposite.