Problem with io

[majidkamali1370]

Hi.
I wrote a class like below:

class MYCLASS
{
   private:
      char Number[100];
   public:
      friend ostream& operator<<(ostream&, MYCLASS&);
      friend ofstream& operator<<(ofstream&, MYCLASS&);
      friend istream& operator>>(istream&, MYCLASS&);
      friend ifstream& operator>>(ifstream&, MYCLASS&);
      . . .
};

Why when I want to read/write from/to a file compiler calls first and third functions?

ofstream_Object << MYCLASS_Object; // this calls first function
ifstream_Object >> MYCLASS_Object; // this calls third function 

[Kyon]

Because ifstream (and ofstream) are just specializations of istream (and ostream), (because of this whenever you call a function (or operator) that takes an ifstream as first operand the one that takes istream is seen as valid too), as indicated in this schematic table:
http://www.cplusplus.com/reference/iostream/

Inverting the order you put the function declarations might (but I guarantee nothing) change the results:

friend ofstream& ...
friend ostream& ...
friend ifstream& ...
friend istream& ...

[chrisname]

I don't understand your question. The compiler resolves the operator to the correct function, doesn't it?

[Kyon]

His problem is that the compiler replaces IF and OF handling to regular I and O handing.

[Galik]

It works as expected for me can we see more of the code?

[majidkamali1370]

I have two other functions except constructor and destructor till now.

MYCLASS& operator=(const MYCLASS& right);
MYCLASS& operator=(const char* rightstring);

first function also works correctly, but second doesn't.
I want to put "char* rightstring" in a file and bring it back and put it in a MYCLASS object.
Actually I want, without pressing any button on keyboard, put "rightstring" in MYCLASS object same as when we use cin object to put some input in an object.