[ibaraku]

What are the uses of the keyword "operator" in c++, I've runned on a couple of definitions but they are not so clear. Can anyone here just give a general idea.
Thanks.

[NickDMax]

C++ allows you to overload operators... That is it allow you to create a custom version of operators such as the + operator. So if I had a class called MyVector and I wanted to define addition for MyVector so that I could use a bit of code like:

MyVector a, b, c;
...
c = a + b;

I can overload the addition operator (+).

Operator overloading

[Bench]

it also allows you to declare conversion operators, which allow safe, implicit casting between classes and other types

for example, if a class had an internal "good" or "bad" state, it might be desirable to be able to evaluate an object inside a conditional statement - This would be a good case for a bool conversion operator

class myclass
{
	bool state;
public:
	myclass() : state(true) {}
	operator bool()
	{
		return state;
	}
}; 

int main()
{
	myclass mc;
	if( mc )
	{
		// 'state' variable in mc is true
	}
} 

This post has been edited by Bench: 07 December 2007 - 03:59 PM

[ibaraku]

NickDMax, on 7 Dec, 2007 - 03:47 PM, said:

C++ allows you to overload operators... That is it allow you to create a custom version of operators such as the + operator. So if I had a class called MyVector and I wanted to define addition for MyVector so that I could use a bit of code like:

MyVector a, b, c;
...
c = a + b;

I can overload the addition operator (+).

Operator overloading

Thanks for the answer and link

[NickDMax]

Bench, on 7 Dec, 2007 - 03:58 PM, said:

it also allows you to declare conversion operators, which allow safe, implicit casting between classes and other types

You know I had COMPLETELY forgotten about that! What is funny is that I saw such a thing not to long ago and sort of squinted at it but it was not until I read your post my memory was jogged and I remembered (if it were not for the example I probably would not have).

thanks.