Re: what is meant by ?

"IceColdFire" <IceColdFire@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:6123E31A-ED23-4EA4-A0FD-D5507A2CF429@xxxxxxxxxxxxx

Hi,

what is meant by
operator int() { return i; }

in a class?

a.a.cpp 

It is a cast or conversion operator. It means that you can use an object of
the class in a context where you would normally use an int and the operator
will substitute i for the class object, e.g.,

class Test
{
public:
   Test(int i_) : i(i_)
   {}
   operator int() { return i; }
private:
   int i;
};

int main()
{
   Test t(6);
   // here we assign the Test object t to the int x. The conversion
   // operator gets called, so we actually assign t.i to x
   int x = t;

   return 0;
}

Conversion operators can be used quite generally. A class might have more
than one so that, chameleon-like, it can take on various forms as the
context requires.

While sometimes convenient, conversion operators can be dangerous in that,
if you make a mistake and use a class object some place where you shouldn't, the conversion operator may allow the code to compile and thereby stop you from discovering the mistake. In other words, conversion operators compromise type safety to some extent.


--
John Carson

.

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