c++ - Operator overloading error "binary '+' : no operator found which takes a left-hand operand" -

class cfruit {  private:   string m_name;  public:    string getname() const;    cfruit(string name = "noname");  }; 

the fruitsalad represented in class cfruitsalad:

class cfruitsalad {  //overloaded operators  friend ostream& operator <<(ostream& out, const cfruitsalad& f);  friend cfruitsalad operator +(const cfruit& f1, const cfruit& f2);   private:   string m_fruitsalad;  public:    cfruitsalad(string content = "");   string getname() const;  }; 

now when use write this:

 cfruit f1("apple");   cfruit f2("orange");   cfruit f3 ("banana");   cfruitsalad fs;   fs = f1 + f2 + f3; //this line generates error   cout << "content: " << fs << endl;  

when compiled program following error received: error c2678: binary '+' : no operator found takes left-hand operand of type 'cfruitsalad' (or there no acceptable conversion)

why error occur , how solve it?

  fs = f1 + f2 + f3;  

no matter order of evaluation (assume f2+ f3 evaluated @ first), first return object of cfruitsalad based on declaration here:

friend cfruitsalad operator +(const cfruit& f1, const cfruit& f2); 

now, next + operation, adding object of cfruit object of cfruitsalad, don't have overloaded version takes 1 cfruit , 1 cfruitsalad, causes error.

you need change implementation of overloaded operator+ (don't overload operators if not meaningful imho).