Comment by Snarwin

  import std.meta: AliasSeq;

  enum E { a, b, c }

  void handle(E e)
  {
      // Need label to break out of 'static foreach'
      Lswitch: final switch (e)
      {
          static foreach (ab; AliasSeq!(E.a, E.b))
          {
              case ab:
                  handleAB();
                  // No comptime switch in D
                  static if (ab == E.a)
                      handleA();
                  else static if (ab == E.b)
                      handleB();
                  else
                      static assert(false, "unreachable");
                  break Lswitch;
          }
          case E.c:
              handleC();
              break;
      }
  }