segfault set_union with object : std::set<CardSet>

Question

Hello all :) I hope someone will have a solution or I will finally find ^^

Context

I am a beginner in c++ so, object, template and iterator maybe I understand a little bit and make some changes but I am not able to manipulate it when it is difficult. I am builing a software using range of hand to evaluate probability in a poker game. I use the library poker stove. https://github.com/andrewprock/pokerstove . In poker we most of time evaluate probability of a hand against another one to win. But we do not know the opponent hand: so we manipulate a range or a set of hands. Here, a hand (2 cards) is a CardSet a structure from pokerstove. So, I have to do set manipulation like intersection, difference, and union.

Problem

I have a problem with union_set but not with set_difference:

std::set<CardSet> union_range;
std::set<CardSet> ensemble_main1=union_range;
std::set<CardSet> ensemble_main2=pourcent_stove(30.);//=range_action(action[0][j][1],j);
std::set<CardSet> ensemble_main=pourcent_stove(20.); //=resultat;
set_difference(ensemble_main1.begin(),ensemble_main1.end(),ensemble_main2.begin(),ensemble_main2.end(),std::inserter(ensemble_main,ensemble_main1.begin()));

Works. pourcent_stove(30.) gives the set of the top 30% 2 cards set of best hands in no limit hold'em.

But:

std::set<CardSet> union_range;
std::set<CardSet> ensemble_main1=union_range;
std::set<CardSet> ensemble_main2=pourcent_stove(30.);//=range_action(action[0][j][1],j);
std::set<CardSet> ensemble_main=pourcent_stove(20.); //=resultat;
set_union(ensemble_main1.begin(),ensemble_main1.end(),ensemble_main2.begin(),ensemble_main2.end(),std::inserter(ensemble_main,ensemble_main1.begin()));

doesn't work: I have a Segfault.

I suppose the problem is here because an union can increase the number of element. Do you have an idea about the line that I can add?

Tries

I have try to do push_back iterator. But without success. It was written that method doesn't exist for this object. I have also try to make a declaration of size for set using the syntaxe of vector: without success

Documents

I have not enough reputation to put links to document I have used. (2 links max)

CardSet code

I have to write the adresse of licence to respect the authors: https://github.com/andrewprock/pokerstove/blob/master/LICENSE.txt

/**
* Copyright (c) 2012 Andrew Prock. All rights reserved.
* $Id: CardSet.h 2649 2012-06-30 04:53:24Z prock $
*/
#ifndef PEVAL_CARDSET_H_
#define PEVAL_CARDSET_H_

#include <iosfwd>
#include <vector>
#include <string>
#include <boost/cstdint.hpp>
#include "Rank.h"
#include "Suit.h"

namespace pokerstove
{
// forward declares
class Card;
class PokerEvaluation;

/**
 * The CardSet is a compact representation of an unordered set of
 * cards.  All evaluation is done at the CardSet level.
 *
 * It can be used to store set of cards such as seen cards, dead
 * cards, folded cards, door cards, and whatever generic set of cards
 * you may be interested in.
 *
 * CardSet is implemented with efficiency in mind, so when selecting
 * from representations for cards, use a CardSet if speed and size
 * efficiency is important.  Other containers may be less efficient in
 * terms of size, speed, or both.
 */
class CardSet
{
public:
    static const size_t STANDARD_DECK_SIZE = Rank::NUM_RANK* Suit::NUM_SUIT;

public:
    CardSet();                                                 //!< defaults to the         empty set
CardSet(const CardSet& cs);                                //!< copy constructor (default)
CardSet(const std::string& c);                             //!< parse cards untill fail
explicit CardSet(const Card& c);                           //!< create a set with one card
explicit CardSet(uint64_t mask) : _cardmask(mask) {}

void   clear() { _cardmask = 0; }                          //!< empty the set
void   fill()  { _cardmask = 0; _cardmask = ~_cardmask; }  //!< put all cards into the set
size_t size() const;                                       //!< return number of cards in set

uint64_t mask() const { return _cardmask; }                //!< 1 bit per card

std::vector<Card> cards() const;                           //!< break into Cards
std::vector<CardSet> cardSets() const;                     //!< break into one card/CardSet

/**
 * Card related methods.
 */
bool contains(const Card& c) const;                        //!< is a card in the set
bool contains(const CardSet& c) const;                     //!< is a card in the set
CardSet& insert(const Card& c);                            //!< add one card
CardSet& insert(const CardSet& c);                         //!< equivalent to |=
CardSet& remove(const Card& c);                            //!< remove a card
CardSet& remove(const CardSet& c);
bool disjoint(const CardSet& c) const { return (_cardmask & c._cardmask) == 0; }
bool intersects(const CardSet& c) const { return !disjoint(c); }

/**
 * Rank related methods.
 */
size_t countRanks() const;
size_t count(const Rank& r) const;
bool   contains(const Rank& r) const;
Card   find(const Rank& r) const;             //!< return some card with rank r, in suit order
int    rankMask() const;                      //!< one bit set for each rank in hand, 13 max
bool   hasStraight() const;
Rank   topRank() const;                       //!< return the highest rank in hand
Rank   bottomRank() const;                    //!< return lowest rank in hand (A plays high)
size_t countMaxRank() const;                  //!< return the number of the most common rank
bool   insertRanks(const CardSet& rset);      //!< add ranks to hand, any suit
CardSet canonizeRanks() const;                //!< create a canonical rank representation

/**
 * Suit related methods.
 */
size_t  countSuits() const;                   //!< number of different suits in hand
size_t  count(const Suit& s) const;           //!< returns the length of the specified suit
size_t  countMaxSuit() const;                 //!< returns the length of the longest suit
bool    contains(const Suit& s) const;
Rank    flushRank(const Suit& s) const;       //!< return the highest rank of specified suit
int     suitMask(const Suit& s) const;
CardSet canonize() const;                     //!< transform suits to canonical form
CardSet canonize(const CardSet& other) const; //!< canonize relative to other hand
CardSet rotateSuits(int c, int d, int h, int s) const;
void    flipSuits();                          //!< invert suit order {cdhs} -> {shdc}

/**
 * String conversions.  Note that the output produced depends on
 * Suit::setSuitStringType (Suit::display s).  Not all string types are
 * reparseable.  That is:
 *
 * CardSet (CardSet("Ac").str()) == CardSet("Ac")
 *
 * May not be true.
 *
 * It is guaranteed to be true if the Suit::display type is SUIT_ASCII
 */
std::string str() const;
std::string rankstr() const;                        //!< print sorted ranks with dupes
std::string toRankBitString() const;

/**
 * indexing utils
 */
size_t colex() const;       //!< return a unique number based on cards
size_t rankColex() const;   //!< return a unique number based on ranks

/**
 * These are the basic building blocks of evaluation, they should
 * be fairly fast, but general, note there is a chance some of
 * these may break if given degenerate sets (with no cards, or
 * more than 7 cards) Every evaluation is ordered such that
 * (better hand) > (worse hand).  This holds even for (esp for)
 * lowball.  There is also a code which represents an null hand,
 * specifcally for the case of not making a qualifying 8 low.
 *
 * There is a tradeoff putting them here, by keeping them here we
 * preserve encapsulation but clutter up the class.  It might be
 * better to separate these out into utility functions.
 * e.g. PokerEvaluation evaluateHigh(const CardSet& c);
 */
PokerEvaluation evaluateHigh() const;
PokerEvaluation evaluateHighRanks() const;
PokerEvaluation evaluateHighFlush() const;
//PokerEvaluation evaluateHighThreeCard() const;
PokerEvaluation evaluateLowA5() const;
PokerEvaluation evaluate8LowA5() const;
PokerEvaluation evaluateLow2to7() const;
PokerEvaluation evaluateRanksLow2to7() const;
PokerEvaluation evaluateSuitsLow2to7() const;
PokerEvaluation evaluate3CP() const;
PokerEvaluation evaluateBadugi() const;
PokerEvaluation evaluatePairing() const;

// sub evaluations

/** return the number of outs to complete a straight
 * returns 8 for open ended
 * returns 4 for gutshot
 * returns 1 for runner runner
 */
int evaluateStraightOuts() const;

// overloaded operators, syntactic sugar. It is no secret that
// this is a bitset, so exposing bit operations should be ok.
// one thing that should be considered is implementing the &=, etc
// operators for efficiency and generality using boost::opperators
void    operator|= (const CardSet& c) { _cardmask |= c._cardmask; }
void    operator^= (const CardSet& c) { _cardmask ^= c._cardmask; }
bool    operator== (const CardSet& c) const { return _cardmask == c._cardmask; }
bool    operator!= (const CardSet& c) const { return _cardmask != c._cardmask; }
bool    operator< (const CardSet& c) const { return _cardmask < c._cardmask; }
bool    operator> (const CardSet& c) const { return _cardmask > c._cardmask; }
CardSet operator& (const CardSet& c) const { return CardSet(_cardmask &  c._cardmask);    }
CardSet operator| (const CardSet& c) const { return CardSet(_cardmask |  c._cardmask); }
CardSet operator^(const CardSet& c) const { return CardSet(_cardmask ^  c._cardmask); }

void swap(CardSet& c)
{
    uint64_t t = c._cardmask;
    c._cardmask = _cardmask;
    _cardmask = t;
}

protected:
void fromString (const std::string& s);   //!< throws exception on parse failre
bool isPaired () const;                   //!< returns true if *any* two cards match rank
bool isTripped () const;                  //!< returns true if trips

private:
//!< bit mask of cards in "canonical" order. [2c,3c ... Ac,Ad ... Ah ... Qs,Ks,As]
uint64_t _cardmask;
};

////////////////////////////////////////////////////////////////////////////////
// Below are standalone methods related to CardSet objects.  They should
// probably be moved to a separate file as they don't directly manipulate
// CardSet data. 
////////////////////////////////////////////////////////////////////////////////


/**
* cannonize a hand relative to a board
*/
CardSet canonizeToBoard(const CardSet& board, const CardSet& hand);


std::vector<int> findSuitPermutation(const CardSet& source, const CardSet& dest);
} // namespace pokerstove


/**
* our little printer
*/
std::ostream& operator<<(std::ostream& sout, const pokerstove::CardSet& e);

#endif  // PEVAL_CARDSET_H_

Thank you for your reading :)

Answer 1

The problem are the last arguments to both set_union and set_difference. The second argument to std::inserter needs to be an iterator to the container that is passed as the first argument. But you're passing an iterator from a different container:

std::inserter(ensemble_main, ensemble_main1.begin())
//                           ^^^^^^^^^^^^^^^^^^^^^^
//                          doesn't point in ensemble_main

You're violating a precondition for the function and that results in undefined behaviour. The fact that set_difference appears to work is just a (un)lucky coincidence.