Thread: A qustion about Vectors with constructors.

I have already settled the second problem
just put #include <algorithm> will fix it.

For the first error, can anyone suggest me how i should do?

Originally Posted by joenching

However, when i try to compile the cpp file, it has two errors:

Code:

Card& Deck::operator[](int index)
{
  if ( index >= 0 && index < 52 )
    return card[index];
}

error C2440: 'return' : cannot convert from 'int' to 'class Card &'
        A reference that is not to 'const' cannot be bound to a non-lvalue

and 1 more i think the reason is i haven't coded the #include <someting> inside the header

Code:

 random_shuffle(card.begin(), card.end());
error C2065: 'random_shuffle' : undeclared identifier

change Card& to int

Thantos:
After i remodifed the program, it can be compiler, however, it has a warning message:

Code:

int Deck::operator[] (int index)
{
  if ( index >= 0 && index < 52 )
    return card[index];
}
 warning C4715: 'Deck::operator[]' : not all control paths return a value

I wanna show you my Card class, I think there should has some interact with card class.
Here is my card.h

Code:

#include <iostream>

using namespace std;

class Card
{
public:

    enum Rank
    {
        ACE,
        TWO,
        THREE,
        FOUR,
        FIVE,
        SIX,
        SEVEN,
        EIGHT,
        NINE,
        TEN,
        JACK,
        QUEEN,
        KING
    };

    enum Suit
    {
        SPADES,
        HEARTS,
        CLUBS,
        DIAMONDS
    };

    Card(); // Default constructor will initialize to Ace of Spades
    Card( Rank newRank, Suit newSuit );

    Rank getRank() const {return rank;}
    Suit getSuit() const {return suit;}

    void setRank( Rank newRank );
    void setSuit( Suit newSuit );

private:

    Rank rank;
    Suit suit;
};

ostream& operator<<( ostream& os, const Card& card );

here is card.cpp

Code:

#include <cassert>
#include <iostream>

#include "card.h"
                    
using namespace std;

Card::Card() :
    rank( ACE ),
    suit( SPADES )
{
}

Card::Card( Rank newRank, Suit newSuit ) :
    rank( newRank ),
    suit( newSuit )
{
}

void Card::setRank( Rank newRank )
{
    rank = newRank;
}

void Card::setSuit( Suit newSuit )
{
    suit = newSuit;
}

ostream& operator<<( ostream& os, const Card& card )
{
    switch( card.getRank() )
    {
        case Card::ACE:
            os << "Ace";
            break;
        case Card::TWO:
            os << "Two";
            break;
        case Card::THREE:
            os << "Three";
            break;
        case Card::FOUR:
            os << "Four";
            break;
        case Card::FIVE:
            os << "Five";
            break;
        case Card::SIX:
            os << "Six";
            break;
        case Card::SEVEN:
            os << "Seven";
            break;
        case Card::EIGHT:
            os << "Eight";
            break;
        case Card::NINE:
            os << "Nine";
            break;
        case Card::TEN:
            os << "Ten";
            break;
        case Card::JACK:
            os << "Jack";
            break;
        case Card::QUEEN:
            os << "Queen";
            break;
        case Card::KING:
            os << "King";
            break;
        default:
            assert( 0 );
    }

    os << " of ";

    switch( card.getSuit() )
    {
        case Card::SPADES:
            os << "Spades";
            break;
        case Card::HEARTS:
            os << "Hearts";
            break;
        case Card::CLUBS:
            os << "Clubs";
            break;
        case Card::DIAMONDS:
            os << "Diamonds";
            break;
        default:
            assert( 0 );
    }

    return os;
}

appericate it

CornedBee

I modified it to that:

Code:

vector<Card> card; // STL vector of type card.

it's almost work, but it still shows a error msg which is same as above when i try to compile it.

Originally Posted by CornedBee

You discared Thantos' comment about doing error handling without ever doing anything like it, and now you're surprised it doesn't work?

Actually, I'd ditch the range test altogether and use vector::at to access the card, that does the range test and the error handling for you.

Doesn't at() throw an exception? If so they might not want to have their program crash just because they gave an invalid range

You mean i need to do the error handling?

Well considering you'll have to do something if they give you an index out of range, yeah you'll have to do some error handling. Either as the class developer or as the class user

It means there has 52 cards in the Deck class
if i want to show the 53 card in that class.
The deck class will throw an error exception?