Member Avatar for Dazaa

Hi,

I want to fill an array with enum Values but using integers in a loop. My set method accepts Enum types and not integers. But when I work with the enums I can use 0,1,2,3 etc.

I am trying to fill a deck of cards using some loops. Is there an easier way to do this than writing loads of code?

enum Suit {Hearts, Clubs, Diamonds, Spades};
enum Value {Two, Three, Four, Five, Six, Seven, Eight, Nine, Ten, Jack, Queen, King, Ace};

//set method for the type that cards is has the signature:
void set(Value v, Suit s);

void Deck::reset(void) {
        int dnumber = 0;


        for(int j=0; j<4; j++) {//suit
            for (int i=0; i<13; i++) { //value
            cards[dnumber].set(i,j); //the compiler doesn't like this line - 
            dnumber++;
            }
        }
    }

I get this:

error: invalid conversion from `int' to `namespace::Value'
error: invalid conversion from `int' to `namespace::Suit'
Edited by mike_2000_17 because: Fixed formatting
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The compile error happens because set is declared to take the enum types (Value, Suit) while the loop is passing plain ints. C++ requires an explicit conversion in this situation, so the compiler rejects the implicit int→enum use. 's advice to convert the loop indices to the enum types is the straightforward fix and follows common C++ practice.

Two practical approaches that keep the intent clear and safe: first, explicitly convert the integer loop indices to the enum types when calling set (use static_cast in modern C++). Before casting, validate the indices because converting an integer that does not correspond to a valid enumerator is implementation-defined and therefore risky. Second, avoid raw numeric bounds entirely by iterating the enum range directly — add a sentinel enumerator (for example ValueCount / SuitCount or LastValue) and loop from the first enumerator to that sentinel. That ties the loop limits to the enum definitions and removes magic numbers like 13 and 4 from the reset logic that fills cards[dnumber].

Additional tips: prefer named constants for counts, use std::array/std::vector for the deck to reduce index mistakes, and consider an overload that accepts integer initializers only if initialization convenience outweighs strict typing. If using C++11 or later, enum class gives stronger typing but still requires explicit conversions when initializing from integers.

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Member Avatar for Dazaa 
enum Suit {Hearts, Clubs, Diamonds, Spades};
enum Value {Two, Three, Four, Five, Six, Seven, Eight, Nine, Ten, Jack, Queen, King, Ace};

//set method for the type that cards is has the signature:
void set(Value v, Suit s);

void Deck::reset(void) {
		int dnumber = 0;
		
		
		for(int j=0; j<4; j++) {//suit
			for (int i=0; i<13; i++) { //value
			cards[dnumber].set(i,j); //the compiler doesn't like this line - 
			dnumber++;
			}
		}
	}
Member Avatar for Fbody

I had a similar example in a book I just read (Beginning C++ Through Game Design). Perhaps try the same technique.
First initialize i and j using values from your enums. Then when calling set() cast the values from int to either Value or Suit as necessary.

From my book's example:

for (int s = Card::CLUBS; s <= Card::SPADES; ++s) {
  for(int r = Card::ACE; r <= Card::KING; ++r) {
    Add(new Card(static_cast<Card::rank>(r), static_cast<Card::suit>(s)));
  }	//end rank for
}	//end suit for

[offTopic]
About the book:
It's not a bad book, it's good for getting going quickly because it covers alot of the basics and just scratches the surface of some of the more complex concepts. I don't think I would consider it a must-have though. It really just glosses over everything it covers and doesn't get very detailed. It has just enough information on each topic to get you going, but you'll need to supplement it with something much more thorough to really learn it well. I won't recommend against it, because you can always learn something new, but I did find most of it to be a little below my current level.[/offTopic]

Edited by Fbody because: n/a
Member Avatar for Dazaa

cool, thanks very much Ill give it a go. I am using Ira Pohl's C++ for C programmers. But I will check out the library for this book you have mentioned.

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