I am referring to the C++23 Standard Draft N4950.
 
 
You can meet me at http://cpp.forum24.ru/ or www.stackoverflow.com or http://ru.stackoverflow.com
 
  
>Вторник, 18 февраля 2025, 0:16 +03:00 от Andrey Semashev via Std-Discussion <std-discussion_at_[hidden]>:
>
>On 2/17/25 23:09, Vladimir Grigoriev via Std-Discussion wrote:
>> In p. 5 of the section 6.2 Declarations and definitions of the C++23
>> Standard there is written
>>
>> 5 In the definition of an object, the type of that object shall not be
>> an incomplete type (6.8), an abstract class type (11.7.4), or a
>> (possibly multi-dimensional) array thereof
>>
>> Also in p.5 of the sub-section 6.8.1 General of the section 6.8 Types
>> there is written
>>
>> ...The type of a pointer to array of unknown bound, or of a type defined
>> by a typedef declaration to be an array of unknown bound, cannot be
>> completed.
>>
>> And further there is followed an example (Example 3)
>>  
>>     class X;             // X is an incomplete type
>>     extern X* xp; // xp is a pointer to an incomplete type
>> extern int arr[]; // the type of arr is incomplete
>> typedef int UNKA[]; // UNKA is an incomplete type
>> UNKA* arrp;    // arrp is a pointer to an incomplete type
>>     UNKA** arrpp;
>>  
>> But according to the first provided quote this object definition
>>
>> UNKA* arrp; // arrp is a pointer to an incomplete type
>>
>> is invalid because such a pointer has an incomplete type.
>>
>> So it looks like the example does not make sense or do I have missed
>> something?
>I'm not sure which version of the standard you're reading, but the
>current wording is different. I'm guessing you're referring to Note 2 in
>paragraph 6:
>
>http://eel.is/c++draft/basic.types.general#6
>
><quote>
>The type of a pointer or reference to array of unknown bound permanently
>points to or refers to an incomplete type.
>An array of unknown bound named by a typedef declaration permanently
>refers to an incomplete type.
>In either case, the array type cannot be completed.
></quote>
>
>Note the text refers to the *array* type, not the *pointer* type. The
>pointer type itself is always complete, even if the pointee type is
>incomplete.
>
>--
>Std-Discussion mailing list
>Std-Discussion_at_[hidden]
>https://lists.isocpp.org/mailman/listinfo.cgi/std-discussion