C++ conditional operator type casting!
itcecsa
is the following expression legal?
D d1;
int i = 3;
i = (i==3) ? d1 : i;
I define a class D which overload operator () to return double. this
is class D.
class D
{
public:
operator double() const
{
return 11.2;
}
};
in the example above, the conditional operator takes 2 operands, one
is of type D, one with type int. I assume it implicitly type cast the
second operand d1 to double. but for g++ on Red Hat it doesn't
compile. this is the error:
operands to ? : have different types.
any ideas why this happens?
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Jiang
> { Please convert tabs to spaces before posting. TIA., -mod/aps }
>
> is the following expression legal?
>
> D d1;
> int i = 3;
> i = (i==3) ? d1 : i;
>
> I define a class D which overload operator () to return double. this
> is class D.
>
> class D
> {
> public:
> operator double() const
> {
> return 11.2;
> }
>
> };
>
> in the example above, the conditional operator takes 2 operands, one
> is of type D, one with type int. I assume it implicitly type cast the
> second operand d1 to double.
Yes, according to 5.6/p5 and 5.6/p3, the conversion is reasonable
since you already defined the conversion explicitly.
> but for g++ on Red Hat it doesn't
> compile. this is the error:
> operands to ? : have different types.
>
> any ideas why this happens?
Seems you are still using GCC 3.3 or 3.4. Try a new one (or even
old one, :-) ) if possible. You above code snippet is not
illegal in my mind.
Regards,
Jiang