On 09/14/2015 11:13 AM, Igor Mironchik wrote:
> Hi,
>
> it seems that problem not in the iterating and deletion from cantainer...
>
> I wrote simple test app and everything is ok.
>
> But something here crashes my app and only in release mode, so I can't
> understand what is the problem...
>
> And ideas?
>
Have you run under valgrind to see if it offers any leads.
> 9/14/2015 6:06 PM, André Somers пишет:
>> Op 14-9-2015 om 16:57 schreef Igor Mironchik:
>>> Hi,
>>>
>>> I ran into this problem...
>>>
>>> void
>>> ImageFilesStoragePrivate::removeAllImages(
>>> QList< ImageRecord> & images,
>>> ImageFilesStorage::ImageType type )
>>> {
>>> QList< ImageRecord>::Iterator it = images.begin();
>>> QList< ImageRecord>::Iterator last = images.end();
>>>
>>> while( it != last )
>>> {
>>> if( (*it).m_type == type )
>>> {
>>> LOG( DebugLogLevel, "Before real deletion" )
>>> removeFromDatabase( it );
>>> LOG( DebugLogLevel, "After real deletion" )
>>>
>>> // it = images.erase( it ); // LOOK AT THIS LINE !!! If I
>>> uncomment it and comment next line - crash...
>>> ++it;
>>>
>>> LOG( DebugLogLevel, QString( "it == last : %1" ).arg( ( it
>>> == last ? "true" : "false" ) ) )
>>> }
>>> else
>>> ++it;
>>> }
>>> }
>>>
>>> What is wrong?
>> A lot is wrong.
>>
>> First, you are not using standard algorithms to do standard things. I'd
>> say std::remove_if with std::erase would be a better way to solve the issue.
>>
>> Then in general, if you delete from the container, iterators are going
>> to be invalidated. Iterate backwards if you are going to delete items
>> from the container.
>>
>> Last: you probably don't want to use QList but QVector.
>>
>> André
>>
>>
>> _______________________________________________
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>> Interest@qt-project.org
>> http://lists.qt-project.org/mailman/listinfo/interest
>
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