C++ Class 析构函数

Question

How do I delete map<char, map<char, char>> board_game , map<int, char> X_index and list<Node*> ?

How would I write a proper destructor for the classes Tree , Node and Boardgame ?

class Search_tree {
    Node* root = nullptr;
    char playerColor;
    list<Node*> leaveNodes;
    
    // Constructor, functions ...

    ~ Search_tree(); <--?
}

class Node {
    Board_game* currentBoard = nullptr;
    Node* parent = nullptr;
    list<Node*> childs;

    // Constructor, functions ...

    ~Node(); <--?
}

class Board_game {
  public:
    // Boardgame
    map<char, map<char, char>> board_game;
    map<int, char> X_index;
    map<int, char> Y_index;
    // Figures
    Position figures[8];

    // Constructor, functions ...

    ~Board_game(); <--?
}

struct Position {
    char x;
    char y;
};

Answer 1

You need to decide who owns what. Then you should turn those "owning" raw pointers into std::unique_ptr and then you won't need hand-written destructors. A possible ownership structure might be:

class Search_tree {
    std::unique_ptr<Node> root;
    char playerColor;
    list<Node*> leaveNodes;
}

class Node {
    Board_game* currentBoard = nullptr;
    Node* parent = nullptr;
    list<std::unique_ptr<Node>> childs;
}

Since Board_game does not contain any raw pointers, it already doesn't need a hand-written destructor.