Function equal_range

include/magic_enum/magic_enum_containers.hpp:121–124

template <typename Cmp = std::less<>, typename BidirIt, typename E>
constexpr auto equal_range(BidirIt begin, BidirIt end, E&& e, Cmp&& comp = {}) {
  const auto first = lower_bound(begin, end, e, comp);
  return std::pair{first, lower_bound(std::make_reverse_iterator(end), std::make_reverse_iterator(first), e, [&comp](auto&& lhs, auto&& rhs) { return comp(rhs, lhs); }).base()};
}

template <typename E = void, typename Cmp = std::less<E>, typename = void>
class indexing {