public:

using OnChange = std::function<std::optional<std::string>(const Option &)>;

Option(const OptionsMap *);

Option(OnChange = nullptr);

Option(bool v, OnChange = nullptr);

Option(const char *v, OnChange = nullptr);

Option(int v, int minv, int maxv, OnChange = nullptr);

Option(const char *v, const char *cur, OnChange = nullptr);

Option &operator=(const std::string &);

operator int() const;

operator std::string() const;

bool operator==(const char *) const;

bool operator!=(const char *) const;

friend std::ostream &operator<<(std::ostream &, const OptionsMap &);

int operator<<(const Option &) = delete;

private:

friend class OptionsMap;

friend class Engine;

friend class Tune;

std::string defaultValue, currentValue, type;

int min, max;

size_t idx;

OnChange on_change;

const OptionsMap *parent = nullptr;

public:

using InfoListener = std::function<void(std::optional<std::string>)>;

OptionsMap() = default;

OptionsMap(const OptionsMap &) = delete;

OptionsMap(OptionsMap &&) = delete;

OptionsMap &operator=(const OptionsMap &) = delete;

OptionsMap &operator=(OptionsMap &&) = delete;

void add_info_listener(InfoListener &&);

void setoption(std::istringstream &);

const Option &operator[](const std::string &) const;

void add(const std::string &, const Option &option);

std::size_t count(const std::string &) const;

private:

friend class Engine;

friend class Option;

friend std::ostream &operator<<(std::ostream &, const OptionsMap &);

// The options container is defined as a std::map

using OptionsStore = std::map<std::string, Option, CaseInsensitiveLess>;

OptionsStore options_map;

InfoListener info;