template<typename Enum>
constexpr Enum get_enum_max()
{
    //static_assert(false, "missing get_enum_max implementation");
    return ~0;
}

template<typename Enum>
const char *get_enum_member_name(Enum val);
// {
//     return nullptr;
// }

#define DECL_ENUM_CLASS_ENUM_MEMBER(enum_name, member_name) member_name,
#define DECL_ENUM_CLASS_MAX_ENUM_MEMBER(enum_name, member_name) case enum_name::member_name: val = enum_name::member_name;

#define DECL_ENUM_CLASS(enum_decl_macro, enum_name)\
enum class enum_name \
{\
enum_decl_macro(DECL_ENUM_CLASS_ENUM_MEMBER, enum_name)\
};\
template<>\
constexpr enum_name get_enum_max<enum_name>()\
{\
    enum_name val{};\
    switch (val)\
    {\
        enum_decl_macro(DECL_ENUM_CLASS_MAX_ENUM_MEMBER, enum_name)\
    }\
    return val;\
}\
\
template<>\
const char *get_enum_member_name<enum_name>(enum_name val)

#define DEF_ENUM_CLASS_STRING(enum_name, member_name) case enum_name::member_name: return #member_name;
#define DEF_ENUM_CLASS(enum_decl_macro, enum_name)\
template<>\
const char *get_enum_member_name<enum_name>(enum_name val)\
{\
    switch (val) {\
        enum_decl_macro(DECL_ENUM_CLASS_MAX_ENUM_MEMBER, enum_name)\
    }\
    return "UNKNOWN";\
}\
template<>\
const char *get_enum_member_name<enum_name>(enum_name val)



#define ENUMCLASS_E(x, enum_name) \
    x(enum_name, A)\
    x(enum_name, B)\
    x(enum_name, C)\
    x(enum_name, D)
DECL_ENUM_CLASS(ENUMCLASS_E, E);
DEF_ENUM_CLASS(ENUMCLASS_E, E);

int main()
{
    constexpr auto i = int(get_enum_max<E>());
    return i;
}