Re: Q. about POD with const member (or g++ vs. Comeau)

[Stefan Naewe <stefan dot naewe at atlas-elektronik dot com>]

On 6/27/2008 12:34 PM, Andrew Haley wrote:
> Stefan Naewe wrote:
>> Given the following:
>>
>>
>> // ++ CODE
>> struct S
>> {
>>   const int ci;
>> };
>>
>> int main()
>> {
>>   S  * s = new S;
>> }
>> // -- CODE
>>
>>
>> Comeau Online gives me:
>>
>> // ++ output
>> Comeau C/C++ 4.3.10.1 (May 29 2008 09:37:15) for ONLINE_EVALUATION_BETA1
>> Copyright 1988-2008 Comeau Computing.  All rights reserved.
>> MODE:strict errors C++ C++0x_extensions
>>
>> "ComeauTest.c", line 1: warning: class "S" defines no constructor to
>> initialize the
>>           following:
>>             const member "S::ci"
>>   struct S
>>          ^
>>
>> "ComeauTest.c", line 8: error: object has an uninitialized const or
>> reference member
>>     S  * s = new S;
>>                  ^
>>
>> 1 error detected in the compilation of "ComeauTest.c".
>>
>> // -- output
>>
>>
>> Different g++ versions
>> 4.2.3
>> 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)
>> gcc version 4.3.1 20080404 (prerelease) [gcc-4_3-branch revision 133917]
>>         (Ubuntu 20080404-0ubuntu1)
>>
>> give:
>>
>> // ++ output
>> constmember.cc: In function 'int main()':
>> constmember.cc:8: warning: unused variable 's'
>> // -- output
>>
>>
>> Reading 5.3.4.15 (and 8.5.5) of the holy standard
>> I'd say Comeau is right, the program is ill-formed, isn't it?
> 
> Yes.

'Yes'
  as in
'Yes, the program is ill formed'

or

'Yes'
  as in
'Yes, the program is ill formed and there's a bug in GCC'

??

> ISO/IEC 14882:1998(E)
> 12.6.2 Initializing bases and members, Para 4
> 
> "If the entity is a nonstatic data member of a const-qualified type,
> the entity class shall have a user-declared default constructor."
> 
> Andrew.


Thanks

Stefan
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