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c++vectoriteratoreraseuser-defined

Deleting user-defined elements in the middle of a vector

I'm coding a program where I want to draw a card, and then delete so that it doesn't get drawn again.

I have a vector of Cards (class containing 2 structs that define Suit and Value) called deck and I don't really know how to use iterators very well, here a code snippet:

void Player::discardCard(CardDeck masterDeck)
{
    cout << "Erasing: " << masterDeck.getDeck().at(cardSelect).toString() << endl;
    /*Attempt1*/
    masterDeck.getDeck().erase(masterDeck.getDeck().begin()+cardSelect);

    /*Attempt 2*/
    vector<Card>::iterator itr;
    itr = masterDeck.getDeck().begin() + cardSelect;
    masterDeck.getDeck().erase(itr);
}

cardSelect has the location of the card I'm going to delete. It's generated randomly within the boundaries of 0 and the size of deck; therefore it shouldn't be pointing to a position out of boundaries.

Everytime I compile I get the following error:

"Expression: vector erase iterator outside range"

I really don't know what to do, hopefully someonw can help me, thanks in advance!

Solution

  • My bet is that getDeck returns the vector by value. It causes itr to point to and erase to operate on different copies of the vector. Thus you get the error. You should return the vector by reference. Change getDeck signature to this one:

    vector<Card>& getDeck()