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Comment by uecker | Hacker News Reader

Are X macros awkward? I find them very straightforward and clear.

The implementation doesn't look too bad, but the usage is terrible:

  #define E_LIST(X) \
      X(V0) X(V1) X(V2) X(V3)

  DEFINE_ENUM(E, E_LIST)

That's not how I want to declare my enums...

To be honest there are ways to make that much nicer. I believe that if you use recursive macros using the VA_OPT feature, you should be able to provide enumerators directly to define enum as a list.

The underlying machinery implementation is going to be much uglier and complex, though.

See https://www.scs.stanford.edu/~dm/blog/va-opt.html

Oh, I didn't know about __VA_OPT__(), thanks for that!

That looks much nicer indeed, but I still vastly prefer the other solutions, simply because I can just declare regular enums.

In practice it is written like like this:

  #define MY_ENUM(x) x(MY_A) x(MY_B) x(MY_C)
  enum my_enum { MY_ENUM(ENUM_ENTRIES) };

  static const char *my_enum_names[] = { MY_ENUM(ENUM_NAMES) };

but one could also make it even more compact if one cared.

That doesn't look any better.

Yes, xmacros have the best compile times, but you can't possibly argue that they are elegant to use compared to the alternatives.

It looks better to me than the other macro solution as it is more transparent what is done compared to DEFINE_ENUM. But I agree it is not as succinct as C++'s reflection syntax.

> It looks better to me than the other macro solution as it is more transparent what is done compared to DEFINE_ENUM.

Fair enough.

They are gross but... effective so shrug

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