In my opinion you are wrong. It is indeed a defect in the standard description that only confuses readers. At least there can be used the term templated function call operator instead of the function call operator.
 
By the way in the C++20 Standard there is even no definition of the term templated function. If I am not mistaken it appears only in the C++23 but nevertheless is not clear:
 
«A templated function is a function template or a function that is templated.»
 
What does «a function that is templated» mean?!
 
The text of the Standard shall be rewritten. As is it is very and very bad and takes too much time to understand what is written in the Standard.
 
With best regards
(Vlad from Moscow)
 
 
 
 
You can meet me at http://cpp.forum24.ru/ or www.stackoverflow.com or http://ru.stackoverflow.com
 
  
>Среда, 2 апреля 2025, 19:29 +03:00 от Andrew Schepler <aschepler_at_[hidden]>:
>
>On Wed, Apr 2, 2025 at 10:45AM Vladimir Grigoriev via Std-Discussion < std-discussion_at_[hidden] > wrote:
>>It just means that the provided quote in the C++ Standard and other similar quotes are incorrect. There must be included somehow the term «templated entities» to make the quotes clear what they are saying about. In my opinion it is a serious defect of the Standard because in other place of the Standard there is written:
>>
>>4 The optional requires-clause in an init-declarator or member-declarator shall be present only if the declarator declares a templated function.
>
>I don't think this is a Standard defect. A non-templated lambda with requires-clause is syntactically valid. The call operator of its closure type has that same requires-clause. But that call operator is semantically invalid because of that very rule you quoted ([dcl.decl.general] p4). So the program is ill-formed. The existing Standard wording is sufficient.
>
>There are plenty of other semantic requirements which must be checked for a closure type or its members, where the lambda expression itself wouldn't violate the wording of the same rule.
>
>-- Andrew Schepler
>
>>
>>The provided by me quote should be looked like for example:
>>
>>«...The trailing requires-clause of a templated entity that is either the function call operator or operator template is the requires-clause of the lambda-declarator, if any.»
>>
>>With best regards
>>(Vlad from Moscow)
>>
>>
>>You can meet me at http://cpp.forum24.ru/ or www.stackoverflow.com or http://ru.stackoverflow.com
>> 
>> 
>>>Среда, 2 апреля 2025, 1:02 +03:00 от Christof Meerwald < cmeerw_at_[hidden] >:
>>>
>>>On Wed, Apr 02, 2025 at 12:33:51AM +0300, Vladimir Grigoriev via Std-Discussion wrote:
>>>>
>>>> In the paragraph #3 of the section «7.5.5.1 Closure types» of the C++20 Standard there is written
>>>>
>>>> «...The trailing requires-clause of the function call operator or operator template is the requires-clause of the lambda-declarator, if any.»
>>>>
>>>> So can a non-generic lambda have a trailing requires clause? And if the text of the quote is correct why is not there an example of such a lambda?
>>>Sure, it just needs to be templated, e.g.
>>>
>>> template<bool B>
>>> void f()
>>>  {
>>>    [] () requires B { } ();
>>>  }
>>>
>>>
>>>There isn't an example for every feature in the standard as the
>>>standard is not a tutorial. Anything surprising or non-obvious should
>>>be highlighted by having an example in the standard.
>>>
>>>
>>>Christof
>>>
>>>--
>>>https://cmeerw.org sip:cmeerw at cmeerw.org
>>>mailto: cmeerw at cmeerw.org xmpp:cmeerw at cmeerw.org
>> --
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