How to create a typecast operator for a class?

Question

I have a complex class:

https://code.sololearn.com/cBtitZp78PHp/?ref=app

I now wish to do the following:

cout<<Complex(4,4);

But, I get a lot of errors, like unable to bind rvalue reference as lvalue to ostream object, etc.

How can I define a function to achieve the typecast we are able to do for integers and other fundamental data types?

Please help!

Answer 1

@Kinshuk
I think this is what you are looking for

https://code.sololearn.com/c82FZrifeo07/?ref=app

Answer 2

... this is not what you want is it?

friend ostream& operator<<(ostream &output, Complex c) {
output << c.Re() << ", " << c.Im();
return output;
}

https://code.sololearn.com/cRhKLnJHWX2n/#cpp

Answer 3

https://www.sololearn.com/discuss/501218/?ref=app

Answer 4

Iff you are stuck you can always go bavk to the course and refer

Answer 5

@jay
I have the ostream& operator << overload, and can do this:

Complex a(2,2);
cout<<a<<endl;

But I am unable to print like this:

cout<<Complex(4,4)<<endl;

while we can print like this:

cout<<int(32.5)<<endl;

Answer 6

@jay
Lemme try...

Hmm, its printing 4,4 on CppDroid as well.

Guess there is still a problem with Code PlayGround...

Answer 7

😀 when isnt there a problem!

edit: I will take down your code now from my profile

Answer 8

@jay
Thank You very much!

Now, I wish to get the real 'typecast function', like: int a = int(22.22);
For my complex class...
How to create such a function so that,
Complex(2.33,'A') is saved as 2.33, 65 ?

Answer 9

Works like that in the code I did. I couldnt find the overload you did. I will look again

edit: still can't see where you overloaded

Answer 10

Dang.. this notification got lost..I will look see. Edit: I think that the easiest method without looking at the code again would be to create a template for complex. maybe

Answer 11

you can set the pair to any data type.

int, float
dbl dbl
etc

Answer 12

but yes. you could do the same with your functions

Answer 13

i will demonstrate code when i get home

Answer 14

https://code.sololearn.com/czpRM40uGsGN/?ref=app

edits in progress, but you get the idea.

Answer 15

@jay
Yours is printing -0, -0 idk why...
The values, aren't being saved for use I think.
Mine has the following prototype, thats why there is an error:

friend ostream& operator << (ostream&, Complex&);
//Now rvalues can't be passed, can they?

Answer 16

template <class aType, class aType2>
class Complex {
private:
aType real;
aType2 imag;
public:

Complex(aType re = 0, aType2 im = 0) :real(re), imag(im) {}
//etc etc
}
// in main
cout << Complex<int, char>(4, 'A');

Answer 17

I think @Complex has the answer

Answer 18

i know works on pc, but not here.. keeps asking for input too

Answer 19

@Kinshuk. I do not know.. I changed my prototype to that of above and it still works on the pc..

well it outputs real, imaginary;
which is I assume is what you want

Answer 20

@jay
That will make it more like a pair, wouldn't it?
I need something to perform explicit conversions from fundamental data types to complex...