------- Comment #4 from federico dot carminati at cern dot ch 2006-10-05 07:44
-------
Subject: Re: Ambiguous warning with -Weffc++
Thanks for your answer. However, if I just code in the following way
int f(a lhc) {
if (lhs) return TRUE;
else if g() return TRUE;
return FALSE
}
I am not always evaluating both arguments, but the warning will still
be there. Or am I missing something? Bes,t
Federico Carminati
CERN-PH
1211 Geneva 23
Switzerland
Tel: +41 22 76 74959
Fax: +41 22 76 79480
Mobile: +41 76 487 4843
On 5 Oct 2006, at 07:18, pinskia at gcc dot gnu dot org wrote:
>
>
> ------- Comment #3 from pinskia at gcc dot gnu dot org 2006-10-05
> 05:18 -------
> (In reply to comment #2)
>> Subject: Re: Ambiguous warning with -Weffc++
>>
>> First of all a user can implement the correct behaviour, evaluating
>> just the first member and returning if true, continuing if false.
>> Second, the compiler tells me that I am evaluating the two members
>> when it has no way to tell this just by looking at the declaration of
>> the operator. So the warning is at best not justified when referring
>> only to the declaration, at worst wrong.
>
> You are incorrect thinking the user can implement the old behavior
> here as the
> compiler needs to evaluate it to pass to the function.
>
> And example about this is talking about:
> struct a {
> bool operator||(const a&);
> //operator bool();
> };
>
> a g();
>
> int f(a lhs)
> {
> return lhs || g();
> }
> ----
> In the non user defined case, lhs is evaulated and if that is true,
> we don't
> call g() at all. In the user defined case, both lhs and g() are
> evaulated as
> we need to call lhs.operator|| with the argument of the value of g().
>
> What it means by both arguments, it means both the left hand side
> (this) and
> the right hand side, the argument to the member operator. This is
> the correct
> warning and just from the sound of it, you don't understand how the
> builtin
> operator|| works or how having an user declared operator|| can work
> without
> evaulating both sides.
>
>
> --
>
> pinskia at gcc dot gnu dot org changed:
>
> What |Removed |Added
> ----------------------------------------------------------------------
> ------
> Status|UNCONFIRMED |RESOLVED
> Resolution| |INVALID
>
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29348
>
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--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29348
