Перегрузка операторов сравнения

void insert_helper(std::shared_ptr<BTreeItem> m_root,const std::shared_ptr<Figure>& figure)
{
    std::shared_ptr<BTreeItem> node = m_root;
        
        if(*figure < *(node->getFigure())) {

class Btree
{
public:
    Btree();
    
    void bstInsert(const std::shared_ptr<Figure>& figure);//!
    void bstRemove(const std::shared_ptr<Figure>& figure);//!
    void Insert(const std::shared_ptr<Figure>& figure);
    
 
    friend std::ostream& operator << (std::ostream& os, const Btree& Btree); //!
    
private:
    std::shared_ptr<BTreeItem> m_root;
};
 
 
class BTreeItem
{
public:
    BTreeItem(const std::shared_ptr<Figure>& figure);
    friend std::ostream& operator << (std::ostream& os, const BTreeItem& obj);
 
 
    void setLeft(std::shared_ptr<BTreeItem> left); 
    void setRight(std::shared_ptr<BTreeItem> right);
    std::shared_ptr<BTreeItem> getLeft();
    std::shared_ptr<BTreeItem> getRight();
    std::shared_ptr<Figure> getFigure() const;  
 
 
 
private:
std::shared_ptr<Figure> m_figure;
std::shared_ptr<BTreeItem> m_left;
std::shared_ptr<BTreeItem> m_right;
};

class Figure
{
public:
    virtual ~Figure() {} //деструктор класса
    virtual void print() const = 0;
    virtual double area() const = 0;
};

bool Figure::operator > (const Figure& rhs) const
{
  return area() > rhs.area();
}
bool Figure::operator < (const Figure& rhs) const
{
  return area() < rhs.area();
}