Class lsst::afw::table::FunctorKey

template<typename T>
class FunctorKey : public lsst::afw::table::OutputFunctorKey<T>, public lsst::afw::table::InputFunctorKey<T>

Convenience base class that combines the OutputFunctorKey and InputFunctorKey

Most objects that can set a calculated or compound value from a record can also get that value back, so we provide this class to aggregate those interfaces.