Pimpl copying

[Peter Kümmel]

André Wöbbeking wrote:
> On Friday 14 July 2006 16:42, Peter Kümmel wrote:
>> Peter Kümmel wrote:
>>> The problem is that KTempDirTest uses the Pimpl idiom, but does
>>> not define a copy ctor/operator, so all private data gets lost
>>> on copying, nor does it forbid copying.
>>>
>>> I fear kdelibs is full of this bug and think we should catch
>>> such constructs at compile time.
>>>
>>> Shouldn't we introduce a coding policy something like this:
>> I've solved the issue by this patch:
>>
>> SVN commit 562284 by kuemmel:
>>
>> macro for pimpl handling:
>>  * consistent naming of the private implementation
>>  * explicit copying, checked by the linker
>>  * disable copying, checked at compile time
>>  * const pimpl
>>
>>
>>  M  +1 -0      TODO
>>  M  +2 -2      kdecore/ktempdir.cpp
>>  M  +1 -2      kdecore/ktempdir.h
>>  M  +2 -2      kdecore/tests/ktempdirtest.cpp
>>  M  +62 -0     kdemacros.h.cmake
> 
>> --- trunk/KDE/kdelibs/TODO #562283:562284
>> @@ -10,6 +10,7 @@
>>    help prevent mistakes where developers forget to delete the
>> pointer. Maybe make use of
>>    Qt4 helper macros?
>>    (Frerich)
>> +  Use KDE_PIMPL_EN(DIS)ABLE_COPY to avoid compiler generated copy
>> functions (Kümmel)
>>
>>  - Move all utility functions away from KApplication. TBD: Make
>> KApplication a very thin wrapper around QApplication. Ideally,
>> KApplication should go --- trunk/KDE/kdelibs/kdecore/ktempdir.cpp
>> #562283:562284
>> @@ -53,7 +53,7 @@
>>  #include <kdebug.h>
>>  #include "kde_file.h"
>>
>> -class KTempDir::Private
>> +class KTempDir::KTempDirPrivate
> 
> Many pimpls were just changed to (nested) Private.
> 

Have the guide lines changed again?

http://lists.kde.org/?l=kde-core-devel&m=114322798807520&w=2
http://developer.kde.org/policies/librarypolicy.html

>> +
>> +#define KDE_PIMPL_BASE_MACRO(COPY_ACCESS,X) \
>> +COPY_ACCESS: \
>> +    X(const X##&); \
>> +    X##& operator=(const X##&); \
>> +private: \
>> +    class X##Private; \
>> +    X##Private * const d;
>> +
>> +#define KDE_PIMPL_ENABLE_COPY(X)  KDE_PIMPL_BASE_MACRO(public, X)
>> +#define KDE_PIMPL_DISABLE_COPY(X) KDE_PIMPL_BASE_MACRO(private,X)
> 
> Does't KDE_PIMPL_DISABLE_COPY lead to unresolved smybols linking error 
> with MSVC (see "unresolved symbols from value.cpp/.h" on k-c-d from 
> 20.01.2006)?
> 
>