C++ STD中的多态性：列表> T >：：迭代器_C++_Segmentation Fault_Polymorphism_Virtual_Invocation

C++ STD中的多态性：列表> T >：：迭代器

c++

C++ STD中的多态性：列表> T >：：迭代器,c++,segmentation-fault,polymorphism,virtual,invocation,C++,Segmentation Fault,Polymorphism,Virtual,Invocation,忽略很多细节：假设我有一个包含函数的抽象卡片类：虚拟int getType=0 由抽象绿卡派生，其中有虚拟int getType=0；还有然后，绿卡由非抽象跟随者和定义纯虚拟的项目导出： int getType(){ return 1;} 在追随者阶级和 int getType(){ return 2;} 在Item类中稍后，我创建并填写一个绿卡指针列表名单*手 …我想根据循环中的手牌类型打印手牌： list<GreenCard *>::iterator i

忽略很多细节：假设我有一个包含函数的抽象卡片类：虚拟int getType=0

由抽象绿卡派生，其中有虚拟int getType=0；还有

然后，绿卡由非抽象跟随者和定义纯虚拟的项目导出：

int getType(){ return 1;}

在追随者阶级和

int getType(){ return 2;}

在Item类中

稍后，我创建并填写一个绿卡指针列表

名单*手

…我想根据循环中的手牌类型打印手牌：

    list<GreenCard *>::iterator it;

    for(it=hand->begin() ; it!=hand->end() ; ++i){
        tp.getCorrectType(*it);
            ...
    }

我确信该卡是正确创建和初始化的，因为就在前一行中，我写入了gdb:p*卡 …我可以看到它的所有字段卡，绿卡和项目相关的是，这是一个'项目'是正确的

编辑：好，下面是一些代码：

class Player{

    list<GreenCard*>*   fateDeck;
    list<GreenCard*>*   hand;
    static const int START_HAND = 4;

    Player(){ 
        fateDeck = new list<GreenCard*> ();
        hand = new list<GreenCard*>();
    }

    void initialize(){
        DeckBuilder db;

        *fateDeck = *(db.createFateDeck() );

        db.deckShuffler(fateDeck);
        initializeHand();
     }

    void initializeHand(){
        for(int counter=0 ; counter<START_HAND ; counter++){
            drawFateCard();
}

    void drawFateCard(){
        hand->push_front(fateDeck->front());
        fateDeck->pop_front();
        cout<<'\n'<<"Drawing from fate deck..."<<'\n'<<endl;
    }

    void Player::printHand(){

        TypeConverter tp;
        list<GreenCard *>::iterator it;

         cout<<"You have " << hand->size()<<" fate cards in hand"<<'\n'
         <<"They are the following:"<<endl;

         for(it=hand->begin() ; it!=hand->end() ; ++it){
             tp.getCorrectType(*it);
             // printing depending on type
         }
    }

    void startingPhase(){
        printHand();
    }
}

class DeckBuilder
{
private:
    list<GreenCard*>* green;

public:
    DeckBuilder();
    list<GreenCard *>* createFateDeck();

    void deckShuffler(list<GreenCard*>* green);
}; 

DeckBuilder :: DeckBuilder()
{  
    green = new list<GreenCard*>();
    srand ( unsigned ( time (NULL) ) );
}

list<GreenCard *>* DeckBuilder :: createFateDeck()
{
    int i;
    for(i=0;i<40;i++)  green->push_back(new Follower());
    return green;
}

void DeckBuilder :: deckShuffler(list<GreenCard*>* green)
{
    vector<GreenCard *> vect;
    list<GreenCard*> ::iterator it;
    for(it = green->begin();it!=green->end();it++)
        vect.push_back((*it));

            random_shuffle ( vect.begin(), vect.end() );

            green->clear();

            vector<GreenCard*>:: iterator it2;
            for(it2 = vect.begin();it2!=vect.end();it2++)
                green->push_back((*it2));
}

印刷品中的缺陷

我把你给我的信息拼凑起来了。使用Visual Studio 2013编译和运行时不会出现分段错误：

#include "stdafx.h"

#include <algorithm>
#include <iostream>
#include <vector>
#include <list>
#include <ctime>

using namespace std;

class Card
{
public:
    virtual int getType() = 0;
};

class GreenCard : public Card
{
public:
    virtual int getType() = 0;
};

class Follower : public GreenCard
{
public:
    int getType(){ return 1; }
};

class Item : public GreenCard
{
public:
    int getType(){ return 2; }
};

class TypeConverter
{
public:
    void getCorrectType(GreenCard* card)
    {
    if (card->getType() == 1)
        std::cout << "Follower" << std::endl;
        if (card->getType() == 2){
        std::cout << "Item" << std::endl;
    }
}
};

class DeckBuilder
{
private:
    list<GreenCard*>* green;

public:
    DeckBuilder();
    list<GreenCard *>* createFateDeck();

    void deckShuffler(list<GreenCard*>* green);
};

DeckBuilder::DeckBuilder()
{
    green = new list<GreenCard*>();
    srand(unsigned(time(NULL)));
}

list<GreenCard *>* DeckBuilder::createFateDeck()
{
    int i;
    for (i = 0; i < 40; i++)  green->push_back(new Follower());
    return green;
}

void DeckBuilder::deckShuffler(list<GreenCard*>* green)
{
    vector<GreenCard *> vect;
    list<GreenCard*> ::iterator it;
    for (it = green->begin(); it != green->end(); it++)
        vect.push_back((*it));

    random_shuffle(vect.begin(), vect.end());

    green->clear();

    vector<GreenCard*>::iterator it2;
    for (it2 = vect.begin(); it2 != vect.end(); it2++)
        green->push_back((*it2));
}

class Player{
    public:
    list<GreenCard*>*   fateDeck;
    list<GreenCard*>*   hand;
    static const int START_HAND = 4;

    Player(){
        fateDeck = new list<GreenCard*>();
        hand = new list<GreenCard*>();
    }

    void initialize(){
        DeckBuilder db;

        *fateDeck = *(db.createFateDeck());

        db.deckShuffler(fateDeck);
        initializeHand();
    }

    void initializeHand(){
        for (int counter = 0; counter < START_HAND; counter++){
            drawFateCard();
        }
    }

    void drawFateCard(){
        hand->push_front(fateDeck->front());
        fateDeck->pop_front();
        cout << '\n' << "Drawing from fate deck..." << '\n' << endl;
    }

    void Player::printHand(){

        TypeConverter tp;
        list<GreenCard *>::iterator it;

        cout << "You have " << hand->size() << " fate cards in hand" << '\n'
            << "They are the following:" << endl;

        for (it = hand->begin(); it != hand->end(); ++it){
            tp.getCorrectType(*it);
            // printing depending on type
        }
    }

    void startingPhase(){
        printHand();
    }


};

int _tmain(int argc, _TCHAR* argv[])
{
    Player pl;
    pl.initialize();
    pl.startingPhase();
    return 0;
}

请提供一个小的、独立的示例来演示错误。

您能在列表中显示代码吗？分段故障输出？同上。看起来列表中的指针坏了。您是否可以选择使用智能指针，例如共享指针而不是原始指针？另外，您没有说明tp.getCorrectType中的tp是什么…您可能已经删除了列表所指向的对象，但是您没有发布填充列表的代码，这可能是问题的根源。该对象可能已被删除，这将导致以后访问该对象时出现SIGSEV；或者可能内存已被释放，只是没有其他内容覆盖了它。我不知道您的调试器在这种情况下是如何工作的。@user2409839-那么您希望它如何帮助您呢？你声称你所做的一切都是错的，但有些事情是错的。我们只有一个循环，您可以显示有效的C++代码和函数调用。那真的没用。我和我的同事已经进行了深入的研究，但仍然无法证明这一错误的合理性，有什么想法可以解释为什么会发生这种情况吗？？这是错误的结论。每次撞车都是有道理的。你只是还没有找到坠机的原因。

Player pl();
pl.initialize();
pl.startingPhase;

#include "stdafx.h"

#include <algorithm>
#include <iostream>
#include <vector>
#include <list>
#include <ctime>

using namespace std;

class Card
{
public:
    virtual int getType() = 0;
};

class GreenCard : public Card
{
public:
    virtual int getType() = 0;
};

class Follower : public GreenCard
{
public:
    int getType(){ return 1; }
};

class Item : public GreenCard
{
public:
    int getType(){ return 2; }
};

class TypeConverter
{
public:
    void getCorrectType(GreenCard* card)
    {
    if (card->getType() == 1)
        std::cout << "Follower" << std::endl;
        if (card->getType() == 2){
        std::cout << "Item" << std::endl;
    }
}
};

class DeckBuilder
{
private:
    list<GreenCard*>* green;

public:
    DeckBuilder();
    list<GreenCard *>* createFateDeck();

    void deckShuffler(list<GreenCard*>* green);
};

DeckBuilder::DeckBuilder()
{
    green = new list<GreenCard*>();
    srand(unsigned(time(NULL)));
}

list<GreenCard *>* DeckBuilder::createFateDeck()
{
    int i;
    for (i = 0; i < 40; i++)  green->push_back(new Follower());
    return green;
}

void DeckBuilder::deckShuffler(list<GreenCard*>* green)
{
    vector<GreenCard *> vect;
    list<GreenCard*> ::iterator it;
    for (it = green->begin(); it != green->end(); it++)
        vect.push_back((*it));

    random_shuffle(vect.begin(), vect.end());

    green->clear();

    vector<GreenCard*>::iterator it2;
    for (it2 = vect.begin(); it2 != vect.end(); it2++)
        green->push_back((*it2));
}

class Player{
    public:
    list<GreenCard*>*   fateDeck;
    list<GreenCard*>*   hand;
    static const int START_HAND = 4;

    Player(){
        fateDeck = new list<GreenCard*>();
        hand = new list<GreenCard*>();
    }

    void initialize(){
        DeckBuilder db;

        *fateDeck = *(db.createFateDeck());

        db.deckShuffler(fateDeck);
        initializeHand();
    }

    void initializeHand(){
        for (int counter = 0; counter < START_HAND; counter++){
            drawFateCard();
        }
    }

    void drawFateCard(){
        hand->push_front(fateDeck->front());
        fateDeck->pop_front();
        cout << '\n' << "Drawing from fate deck..." << '\n' << endl;
    }

    void Player::printHand(){

        TypeConverter tp;
        list<GreenCard *>::iterator it;

        cout << "You have " << hand->size() << " fate cards in hand" << '\n'
            << "They are the following:" << endl;

        for (it = hand->begin(); it != hand->end(); ++it){
            tp.getCorrectType(*it);
            // printing depending on type
        }
    }

    void startingPhase(){
        printHand();
    }


};

int _tmain(int argc, _TCHAR* argv[])
{
    Player pl;
    pl.initialize();
    pl.startingPhase();
    return 0;
}