Stack throws memory access violation

Question

So I am trying to create a simple poker game to re familiarize myself with C++, as I have been out of it for a while and would like to get back into C++.

I am having issues with a stack (appropriate, no?), from the STL. I can't seem to get it to allow me to add anything to the stack. Every time I call the push function on the stack object, it throws a memory access violation... I even tried creating a stack of integers, and adding those to the stack, but it still throws the memory access violation error. Which is weird.

The code that currently adds the object to the stack is:

//shuffles the deck
void Deck::shuffle()
{
    int index;

    for(int i = 0; i < DECK_SIZE; i++)
    {
        index = (rand() % 52);

        if(deck[index].drawn == false)
        {
            shuffledDeck.push(deck[index]); //throws the error
            deck[index].drawn = true;
        }
        else
        {
            i--;
        }
    }
}

I set a break point, and followed it down the rabbit hole, and found out it throws the exception here:

void push_back(const value_type& _Val)
{   // insert element at end
    this->_Orphan_all();
    _PUSH_BACK_BEGIN;            //EXCEPTION!
    this->_Getal().construct(
    this->_Map[_Block] + _Newoff % _DEQUESIZ, _Val);
    _PUSH_BACK_END;
}

Which is located deque.cpp... Which is odd.

For reference, here is the rest of the code I think may be necessary:

Deck.cpp

#include "stdafx.h"
#include "Deck.h"
#include <time.h>

using namespace std;
using namespace CardDeck;

const int DECK_SIZE = 52;



CARD deck[DECK_SIZE];
std::stack<CARD> shuffledDeck;



Deck::Deck()
{
    srand((unsigned int)time(NULL));
    loadCards();
}

Deck::~Deck()
{
}

//Draws a card from the deck
CARD Deck::drawCard()
{
    CARD card = shuffledDeck.front();
    shuffledDeck.pop();
    return card;
}

//shuffles the deck
void Deck::shuffle()
{
    int index;

    for(int i = 0; i < DECK_SIZE; i++)
    {
        index = (rand() % 52);

        if(deck[index].drawn == false)
        {
            shuffledDeck.push(deck[index]);
            deck[index].drawn = true;
        }
        else
        {
            i--;
        }
    }
}

    void Deck::loadCards()
    {

        //create input file stream
        ifstream cardList;

        //open the list of cards
        cardList.open("card.txt", ios::in);

        //if the file has opened successfully
        if(cardList.is_open())
        {
            int index = 0;

            //and while the cardlist has data left
            while(cardList.good())
            {
                char * context = NULL;
                CARD card = CARD();
                //read the cards
                string line;
                getline(cardList, line);

                char * s = strtok_s(&line[0], ", ", &context);

                card.value = *s;

                s = strtok_s(NULL, ", ", &context);

                card.suit = s;
                card.drawn = false;

                deck[index] = card;

                index++;
            }
        }

    }

Deck.h (contains the CARD struct)

#pragma once
#include <string>
#include <stack>
#include <fstream>
#include <sstream>
#include <iostream>
#include <string>

namespace CardDeck
{
    struct CARD
    {
        public:
            std::string suit;
            char value;
            bool drawn;

            CARD(){}

            CARD(const CARD& card)
            {
                suit = card.suit;
                value = card.value;
                drawn = card.drawn;
            }

            CARD& operator= (const CARD& card)
            {
                suit = card.suit;
                value = card.value;
                drawn = card.drawn;

                return *this;
            }
    };

        class Deck
        {
            public:
                Deck();
                ~Deck();
                Deck(const Deck& deck);
                CARD drawCard();
                void shuffle();

            private:
                void loadCards();

        };
    }

Answer 1

You're probably writing past the end of the deck array in loadCards() , corrupting memory.

Even if you have exactly 52 lines of data, cardlist.good() will return true until after an EOF indication.

You might want to try the following loop instead (untested):

string line;
while(getline(cardList, line) && (index < 52))
{
    char * context = NULL;
    CARD card = CARD();

    char * s = strtok_s(&line[0], ", ", &context);

    card.value = *s;

    s = strtok_s(NULL, ", ", &context);

    card.suit = s;
    card.drawn = false;

    deck[index] = card;

    index++;
}