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忽略很多细节：假设我有一个Card包含函数的抽象类： virtual int getType()=0;

由也GreenCard有 a virtual int getType()=0; as well 的抽象派生而来。

然后GreenCard由非抽象派生Follower，Item其中定义了纯虚：

int getType(){ return 1;}

在追随者类和

int getType(){ return 2;}

在 Item 类中。

后来我创建（并填写）GreenCard 指针列表

list<GreenCard*>* hand;

...我想循环打印手牌（取决于它们的类型）：

    list<GreenCard *>::iterator it;

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

在这个函数中，我在第一行得到了 SegFault！

void getCorrectType(GreenCard* card)
{
    /*SF here->*/  if(card->getType()==2){
        ...
    }
}

我确信“卡”已正确创建和初始化，因为在上一行我在 gdb 中写入：p *card ...并且我可以看到它的所有字段（卡、绿卡和项目相关的字段-是的是一个“项目”）蜜蜂是正确的！

编辑：好的，然后是更多代码：

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));
}

最终在 main()

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

和 printHand() 中的段错误；

4

1 回答 1

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我已经把你给我的信息拼凑起来了。这编译和运行没有分段错误（使用 Visual Studio 2013）：

#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示例来演示该错误。

于 2014-04-29T22:54:43.787 回答