JSON.H for BOOLEAN VALUE

class Node;

using Dict = std::map<std::string, Node>;
using Array = std::vector<Node>;
using NodeContainer = std::variant<std::nullptr_t, bool, int, double, std::string, Dict, Array>;

// All methods should throw this error while JSON parsing
class ParsingError : public std::runtime_error {
public:
    using runtime_error::runtime_error;
};

class Node {
public:  // Constructors
    Node() = default;

    Node(std::nullptr_t /* value*/);
    Node(bool value);
    ...

public:  // Methods
    bool IsBool() const;

    const NodeContainer& AsPureNodeContainer() const;
    bool AsBool() const;
    ...

public:  // Operators
    friend bool operator==(const Node& left, const Node& right);
    friend bool operator!=(const Node& left, const Node& right);

private:  // Fields
    NodeContainer data_;
};