Looks like we've got all the data we need here, now to make a corresponding Producer.cpp file containing constructor implementations and with the implementations of get_profitability_yesterday and get_average_profitability_last_seven_days moved into it.

One thing to bear in mind: derived class constructors can't directly initialise their base class' variables, they have to call the base class' constructor.

Also can you rebase this onto master to include recent changes.

I would also really prefer all the maros be prefixed with OV_ or _OV_ depending on expected use case, those which you use directly should be OV_, those you usually don't should be _OV_, and something like value_or_move should be in a namespace even if its in macros like

namespace OpenVic::detail {
    template<typename T>
    constexpr T value_or_move(T&& value);
}

#define MACRO(Arg) ::OpenVic::detail::value_or_move(Arg);

Great work! Once this is merged, "draft for factory production" #144 will automatically re-target itself onto master, however you'll still need to rebase it to fix merge conflicts.