Thanks! That indeed does the equivalent as the Zig code... but feels a bit pointless to do that in D, I think?

Could've done this and be as safe, but perhaps it loses the point of the article:

    enum U { A, B, C }

    void handle(U e)
    {
      with (U)
        final switch (e) {
        case A, B:
          handleAB();
          if (e == A) handleA(); else handleB();
          break;
        case C:
          handleC();
          break;
        }
    }