I don't see a compelling case for a change. As we often say, "the standard
is not a tutorial".

On Mon, Jan 13, 2025 at 5:33 PM mauro russo <ing.russomauro_at_[hidden]>
wrote:

> ok,
>
> it makes sense, as the referred §13.7.3-p4 allows, instead, a template
> member function to be defined as non-overriding the virtual non-template
> one.
>
> Anyway, do you believe that specifying "for G" in §11.7.3 -p2 is just more
> tedious ?
>
>
>
> Il giorno lun 13 gen 2025 alle ore 23:08 Brian Bi <bbi5291_at_[hidden]> ha
> scritto:
>
>>
>>
>> On Mon, Jan 13, 2025 at 5:05 PM mauro russo via Std-Discussion <
>> std-discussion_at_[hidden]> wrote:
>>
>>> In the actual standard draft,
>>>
>>> §11.7.3 [class.virtual] - p2, p6
>>>
>>> read something that seems to be contradiction:
>>>
>>> p2 text:
>>> If a virtual member function F is declared in a class B, and, in a class
>>> D derived (directly or indirectly) from B, a declaration of a member
>>> function G corresponds (6.4.1) to a declaration of F , ignoring trailing
>>> requires-clauses, then G overrides F. ...
>>>
>>> p6 text:
>>> A virtual function shall not have a trailing requires-clause.
>>>
>>> It seems the text of p2 allows the presence of trailing requires-clauses
>>> in virtual functions, both in the original and the overriding declarations
>>> (note the plural in p2 text), whereas p6 text states the opposite.
>>>
>>
>> You don't know whether the derived class function is virtual until you
>> check whether it overrides a virtual function from the base class. So you
>> have to ignore the trailing requires-clause on the derived class function
>> in order to check whether it overrides, and if it does, then the trailing
>> requires-clause is ill-formed.
>>
>>
>>>
>>> However, it's clear that constraints would not be manageable for virtual
>>> functions. Indeed, the comment during the example in p6 also reads more
>>> specifically that "virtual function cannot be constrained ".
>>>
>>> Now, one might think that the part of p2 "ignoring trailing
>>> requires-clauses" does not necessarily mean that they can be present, and
>>> it might be read, instead, as a kind of confirmation that they cannot.
>>> However, why specifying such a detail only for trailing
>>> requires-clauses, not even for type-constraints, and requires-clauses ? I
>>> mean, even these other forms of constraints cannot be present, from
>>> §13.7.3 [temp.mem] - p3 and p4,
>>> p3: "A member function template shall not be declared virtual."
>>> p4: "A specialization of a member function template does not override a
>>> virtual function from a base class."
>>>
>>>
>>> I guess that, for consistency, the part "ignoring trailing
>>> requires-clauses" should be removed.
>>>
>>> --
>>> Std-Discussion mailing list
>>> Std-Discussion_at_[hidden]
>>> https://lists.isocpp.org/mailman/listinfo.cgi/std-discussion
>>>
>>
>>
>> --
>> *Brian Bi*
>>
>

-- 
*Brian Bi*