Function detectTuplePattern

sample/detectTuplePattern.cpp:6–17

template <typename Tuple>
constexpr int32_t detectTuplePattern(Tuple const &tuple)
{
  using namespace matchit;
  return match(tuple)(
      // clang-format off
        pattern | ds(2, ooo, 2) = expr(4),
        pattern | ds(2, ooo   ) = expr(3),
        pattern | ds(ooo, 2   ) = expr(2),
        pattern | ds(ooo      ) = expr(1)
      // clang-format on
  );
}

static_assert(detectTuplePattern(std::make_tuple(2, 3, 5, 7, 2)) == 4);