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POSegfault/ "Vector is not dereferencable" on std::vector push_back
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  1. POSegfault/ "Vector is not dereferencable" on std::vector push_back
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    copied!<p>I have some C++ code dealing with a card game and it's segfaulting and I can't figure out why. I tried running it in MSVS 2012 to get a more clear error and it threw a "Vector is not dereferencable." I tried doing some research but I'm lost on where the error is coming from. I'm guessing the bug isn't in the push_back but rather somewhere else as the problem line works most of the time. The error occurs in Table::hit(). After looking through the code I think the bug may possibly lie in Hand::split() but I am not sure and I am even less sure how to fix it. Thanks!</p> <pre><code>class Hand { public: std::vector&lt;Card&gt; hand; bool active, doubled, isBlackjack, busted; Hand() : active(true), doubled(false), isBlackjack(false), busted(false) { } Hand(const Hand&amp; _hand); void removeCard(Card card) { hand.erase( hand.begin() ); } Card split(); void clear(); int cards() const { return hand.size(); } int getHandValue() const; Card at(int pos) { return hand[pos]; } friend std::ostream&amp; operator&lt;&lt; (std::ostream&amp; out, const Hand&amp; hand); friend std::ostream&amp; operator&lt;&lt; (std::ostream&amp; out, const std::vector&lt;Hand&gt;&amp; hands); }; Hand::Hand(const Hand&amp; _hand) : hand(_hand.hand), active(_hand.active), doubled(_hand.doubled), isBlackjack(_hand.isBlackjack), busted(_hand.busted) { } Card Hand::split() { //COULD THE BELOW CODE BE CAUSING ISSUES? Card card = hand[0]; hand.erase( hand.begin() ); return card; } void Hand::clear() { active = true; hand.clear(); } int Hand::getHandValue() const { int value(0), aces(0); for(std::vector&lt;Card&gt;::const_iterator it = hand.cbegin(); it != hand.cend(); ++it) { value += getCardValue(it-&gt;getRank()); if(it-&gt;getRank() == ACE) ++aces; } while(aces &gt; 0 &amp;&amp; value &gt; 21) { value -= 10; --aces; } return value; } std::ostream&amp; operator&lt;&lt; (std::ostream&amp; out, const Hand&amp; hand) { for(std::vector&lt;Card&gt;::const_iterator it = hand.hand.begin(); it != hand.hand.end(); ++it) { out &lt;&lt; *it &lt;&lt; " "; } out &lt;&lt; hand.getHandValue(); return out; } std::ostream&amp; operator&lt;&lt; (std::ostream&amp; out, const std::vector&lt;Hand&gt;&amp; hands) { for(std::vector&lt;Hand&gt;::const_iterator it = hands.begin(); it != hands.end(); ++it) { out &lt;&lt; *it &lt;&lt; " "; } return out; } class Table { protected: Shoe shoe; Strategy strat; Hand dealer; std::vector&lt; Hand &gt; player; double balance, blackjackPayoff; bool hitSoft17; void deal(); void hit(int split=0); void split(int split=0); double stand(); Action getUserAction(); bool isCurrentGame(); public: Table(int decks, int _balance); double bet; void play(); void print(); void simulate(std::string fileName, int hands); }; Table::Table(int decks, int _balance) : shoe(decks), balance(_balance), blackjackPayoff(1.5), hitSoft17(true), bet(10) {} bool Table::isCurrentGame() { for(std::vector&lt;Hand&gt;::iterator it = player.begin(); it != player.end(); ++it) { if(it-&gt;active) return true; } return false; } void Table::deal() { dealer.clear(); player.clear(); dealer.addCard( shoe.pullCard(true) ); dealer.addCard( shoe.pullCard() ); player.push_back(Hand()); player[0].addCard( shoe.pullCard() ); player[0].addCard( shoe.pullCard() ); if(player[0].getHandValue() == 21 &amp;&amp; dealer.getHandValue() == 21) { player[0].active = false; } else if(player[0].getHandValue() == 21) { player[0].active = false; } else if(dealer.getHandValue() == 21) { player[0].active = false; } } void Table::hit(int split) { player[split].hand.push_back( shoe.pullCard() ); //SEGFAULT HERE if(player[split].getHandValue() &gt; 21) { player[split].active = false; } } void Table::split(int split) { player.push_back(Hand()); player[player.size() - 1].hand.push_back( player[split].split() ); player[split].hand.push_back( shoe.pullCard() ); player[player.size() - 1].hand.push_back( shoe.pullCard() ); if(player[split].getHandValue() == 21) { player[split].active = false; } else if(player[player.size() - 1].getHandValue() == 21) { player[player.size() - 1].active = false; } } double Table::stand() { double winnings(0.0); bool allNats(true); //dealer.push_back( shoe.pullCard() ); for(std::vector&lt;Hand&gt;::iterator it = player.begin(); it != player.end(); ++it) { if(it-&gt;cards() == 2 &amp;&amp; it-&gt;getHandValue() == 21) { winnings += bet * blackjackPayoff; it-&gt;isBlackjack = true; } else { allNats = false; if(it-&gt;getHandValue() &gt; 21) it-&gt;busted = true; } } if(!allNats) { while(dealer.getHandValue() &lt;= 17) { if(dealer.getHandValue() == 17) { //dealer has 17 and doesnt hit soft 17s so hes not going to draw anymore cards if( !hitSoft17 || dealer.cards() != 2 || !(dealer.hand.at(0) == ACE || dealer.hand.at(1) == ACE) ) break; } dealer.addCard( shoe.pullCard() ); } } for(std::vector&lt;Hand&gt;::iterator it = player.begin(); it != player.end(); ++it) { if(!it-&gt;isBlackjack) { if(it-&gt;busted) { if(it-&gt;doubled) winnings -= 2.0 * bet; else winnings -= bet; } else if(dealer.getHandValue() &gt; 21 || dealer.getHandValue() &lt; it-&gt;getHandValue()) { if(it-&gt;doubled) winnings += 2.0 * bet; else winnings += bet; } else if(dealer.getHandValue() &gt; it-&gt;getHandValue()) { if(it-&gt;doubled) winnings -= 2.0 * bet; else winnings -= bet; } } } //only other scenario is a push which we dont do anythign for return winnings; } void Table::simulate(std::string fileName, int hands) { int i(0), countHL; double trueCountHL; std::ofstream ofs(fileName); Action action; while(i &lt; hands) { deal(); VisibleCards vc(player[0].at(0), player[0].at(1), dealer.at(0)); while(isCurrentGame()) { int j(0), q(1); countHL = shoe.getCountHL(); trueCountHL = shoe.getTrueCountHL(); for(int l = 0; l &lt; q; ++l) { while(player[l].active) { if(player[l].cards() == 2) action = getBasicStrategy(player[l].getHandValue(), dealer.at(0).getCardValue(), player[l].at(0).getCardValue(), player[l].at(1).getCardValue()); else action = getBasicStrategy(player[l].getHandValue(), dealer.at(0).getCardValue()); switch(action) { case HIT: hit(j); break; case DOUBLE: hit(j); if(player[l].cards() == 3) { player[l].doubled = true; player[l].active = false; } break; case SPLIT: if(player.size() &lt;= 4) { split(j); ++q; } else hit(j); break; case STAND: player[l].active = false; break; } ++j; } } } double winnings = stand(); balance += winnings; ofs &lt;&lt; std::endl &lt;&lt; std::fixed &lt;&lt; vc &lt;&lt; "," &lt;&lt; winnings &lt;&lt; "," &lt;&lt; std::setprecision(2) &lt;&lt; trueCountHL &lt;&lt; "," &lt;&lt; balance &lt;&lt; "," &lt;&lt; std::setprecision(0) &lt;&lt; countHL &lt;&lt; "," &lt;&lt; shoe.getRemainingDecks(); ofs &lt;&lt; std::endl &lt;&lt; 1; //BlackjackData bjd(winnings, balance, shoe.getTrueCountHL(), shoe.getCountHL(), HIT); //strat.addData(vc, bjd); ++i; } strat.print(fileName); } </code></pre>
 

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