Function is_set

3rd/wildcards/include/wildcards/match.hpp:104–187

template <typename PatternIterator>
constexpr bool is_set(
    PatternIterator p, PatternIterator pend,
    const cards<iterated_item_t<PatternIterator>>& c = cards<iterated_item_t<PatternIterator>>(),
    is_set_state state = is_set_state::open)
{
#if cfg_HAS_CONSTEXPR14

  if (!c.set_enabled)
  {
    return false;
  }

  while (p != pend)
  {
    switch (state)
    {
      case is_set_state::open:
        if (*p != c.set_open)
        {
          return false;
        }

        state = is_set_state::not_or_first;
        break;

      case is_set_state::not_or_first:
        if (*p == c.set_not)
        {
          state = is_set_state::first;
        }
        else
        {
          state = is_set_state::next;
        }

        break;

      case is_set_state::first:
        state = is_set_state::next;
        break;

      case is_set_state::next:
        if (*p == c.set_close)
        {
          return true;
        }

        break;

      default:
#if cfg_HAS_FULL_FEATURED_CONSTEXPR14
        throw std::logic_error(
            "The program execution should never end up here throwing this exception");
#else
        return throw_logic_error(
            "The program execution should never end up here throwing this exception");
#endif
    }