Returning values through params

[cwn723]

Hello, i need help solving this problem:

void main(){
  int length = 0;

  getNumbs(length);

  std:: cout << length << std::endl;
 
  system("Pause");

}

void getNumbs(__out int leng){

	leng = 20;
}

I am trying to return a value through the parameter leng, but the program always prints out 0, what am i doing wrong?

[Galik]

__out is not C++. Use the reference declaration: &

void getNumbs(int& leng){

	leng = 20;
}

[cwn723]

Thanks Galik, that worked, but i see __out used all the time, and it causes no errors to my code. Im pretty sure that it is just a windows macro used to say that a param is used to return a value, not as an input value, it could be helpful to you to organize your code or something.

So:

void getNumbs( __out int& leng){

	leng = 20;
}

is the same as:

void getNumbs( int& leng){

	leng = 20;
}

Thanks again!

[Athar]

That it is an output parameter goes without saying.
If it weren't, it should be a const reference.