template <typename T>   //Special template for EE_PDUs, which are weird
    auto getKey_imp(const T &struc, int &key, int) -> decltype(struc.interesting_member, void())   //If struc has an interesting_member member, this version is used
    {
        key = 0;
    }
    template <typename T>
    void getKey_imp(const T &struc, int &key, long)   //struc didn't have an interesting_member member, do nothing
    {
    }

public:
    template <typename T>
    bool getKey(const T &struc, int &key)
    {
    getKey_imp(struc, key, 0);
    return key == 0;    //Successful?
    }