public:

static td::int64 get_counter_value();

BitString() = default;

explicit BitString(size_t bits);

BitString(std::shared_ptr<char> ptr, size_t offset, size_t size);

explicit BitString(td::Slice key_data);

BitString(const BitString &) = default;

BitString &operator=(const BitString &other);

BitString(BitString &&) noexcept = default;

BitString &operator=(BitString &&other) noexcept;

~BitString();

size_t bit_length() const;

td::uint8 get_bit(size_t pos) const;

bool operator==(const BitString &other) const;

size_t common_prefix_length(const BitString &other) const;

BitString substr(size_t pos, size_t length = SIZE_MAX) const;

friend std::ostream &operator<<(std::ostream &os, const BitString &bits);

friend td::StringBuilder &operator<<(td::StringBuilder &string_builder, const BitString &bits);

template <class StorerT>

friend void store(const BitString &bs, StorerT &storer);

template <class ParserT>

friend BitString fetch_bit_string(ParserT &parser);

template <class ParserT>

friend BitString fetch_bit_string(ParserT &parser, BitString &base_bs);

static td::Result<std::string> serialize_for_network(const BitString &bs);

static td::Result<BitString> fetch_from_network(td::Slice data);

// TODO: make following fields private

std::shared_ptr<char> data_;

size_t bits_size_{};

td::int32 bytes_size_{};

td::uint8 begin_bit_{};

td::uint8 end_bit_{};