'operator <<' why is it not working,the print method. c-CodePudding

I am studying cpp now, when i implement a card class with the print operator it's sad"Invalid operands to binary expression ('std::ostream' (aka 'basic_ostream') and 'const Suits')" .Also, I'm using Xcode for IDE. Thanks for the help!

#include <iostream>




enum class Suits : char {clubs='C',diamonds='D',hearts='H',spades='S'};

enum class Faces : int {two=2, three, four, five, six, seven, eight,
  nine, ten, jack, queen, king, ace /*14*/};
  
class Card {
public:
  
    Card(Faces aFace=Faces::ace, Suits aSuit=Suits::clubs){
        suit=aSuit;
        face=aFace;
    }
  
  ~Card();
  
  
    friend std::ostream &operator<<(std::ostream& output, const Card &s){
        output << s.suit;
            return output;
    }
  
protected:
  Suits suit;
  Faces face;
};

CodePudding user response：

You need to implement std::ostream &operator<<(std::ostream& output, const Suits &s) on top of the Card implementation.

You can simply implement it inside the Suits class, like you did with the Card class.

CodePudding user response：

According to the error message you did not define the operator << for objects of the type Suits that is used within the body of the operator << for objects of the type Card

output << s.suit;

That is you need also to define the operator

std::ostream & operator <<( std::ostream &, const Suits & );

Perhaps you need also to define a similar operator for objects of the type Faces.