protoMemberOf

struct Test
{
  @ProtoTag(2)
  int i;
  @ZigZag
  @ProtoTag(1)
  int j;
}

static assert(protoTagOf!(Test, "i") == 2);
static assert(!isZigZag!(Test, "i"));
static assert(protoMemberOf!Test(2) == "i");
static assert(isZigZag!(Test, "j"));