[vtk-developers] Proposing vtkObjectMacro

[Kyle Lutz]

Thanks all for the input.

For now I'd like to keep the discussion targeted at vtkClassMacro(). A
macro for abstract classes (which VTK has far fewer of) could be added
later if vtkClassMacro() proves useful. Furthermore, I don't really
think using a vtkDisableCopy() type macro is the proper way to
prohibit copying of VTK classes. vtkObjectBase should just declare its
copy constructor and assignment operator as private a la
boost::noncopyable (but this is a larger change than I feel
comfortable making).

I've re-pushed the topic with the constructor and destructor
declarations removed. Now the documentation looks like this:

// Description:
// Declares a vtkObject subclass.
//
// Notably, performs the following actions:
//   - invokes the vtkTypeMacro()
//   - disables its copy constructor and assignment operator
//   - declares its static *New() method
#define vtkClassMacro(className, parentClassName)

-kyle

On Thu, Sep 13, 2012 at 11:49 AM, Marcus D. Hanwell
<marcus.hanwell at kitware.com> wrote:
> That much wasn't clear to me in the other suggestions. I would like to
> see a vtkClassMacro and vtkAbstractClassMacro, and thought that was
> what was being converged on.
>
> On Thu, Sep 13, 2012 at 2:44 PM, Utkarsh Ayachit
> <utkarsh.ayachit at kitware.com> wrote:
>> I am suggesting the vtkDisableCopy() macro as an alternative to the
>> vtkClassMacro() since after stripping out the controversial parts for
>> vtkClassMacro() all that remains is disable copy, vtkTypeMacro() and
>> New() and frankly, New() is also not always needed since it doens't
>> work for abstract classes.
>>
>>
>> On Thu, Sep 13, 2012 at 2:40 PM, Marcus D. Hanwell
>> <marcus.hanwell at kitware.com> wrote:
>>> Why provide a disable copy macro when it is a requirement of vtkObject
>>> derived classes? It should just be part of the vtkClassMacro, with
>>> QObject derived classes they can have copy constructors, and so
>>> provided an option makes more sense there.
>>>
>>> On Thu, Sep 13, 2012 at 2:29 PM, Aashish Chaudhary
>>> <aashish.chaudhary at kitware.com> wrote:
>>>> +1 to remove construct and destructor. Also I think like Qt we should
>>>> provide disable copy macro and use it in vtkClassMacro.
>>>>
>>>> Thanks,
>>>>
>>>>
>>>> On Thu, Sep 13, 2012 at 12:39 PM, Cory Quammen <cquammen at cs.unc.edu> wrote:
>>>>>
>>>>> +1 if you remove the constructors/destructor declarations.
>>>>>
>>>>> Cory
>>>>>
>>>>> On Thu, Sep 13, 2012 at 11:33 AM, Patchett, John M <patchett at lanl.gov>
>>>>> wrote:
>>>>> > Though I don't usually involve myself in VTK development, I think
>>>>> > that obfuscated understandability is part of the reason that I've seen
>>>>> > a large number of otherwise bright developers (students) become
>>>>> > integration impotent when asked to put their ideas/code in
>>>>> > VTK/ParaView...
>>>>> > If a goal is to have contributors, this is a bad idea.
>>>>> >
>>>>> >
>>>>> > --John.
>>>>> >
>>>>> >
>>>>> > On 9/13/12 9:22 AM, "Marcus D. Hanwell" <marcus.hanwell at kitware.com>
>>>>> > wrote:
>>>>> >
>>>>> >>On Thu, Sep 13, 2012 at 11:07 AM, Utkarsh Ayachit
>>>>> >><utkarsh.ayachit at kitware.com> wrote:
>>>>> >>>> I am in favor of adding the macro, and disagree with Utkarsh in that
>>>>> >>>> we already have the type macro etc and it will remove the need for a
>>>>> >>>> lot of boiler plate code in each class declaration.
>>>>> >>>
>>>>> >>> Note  that vtkTypeMacro() doesn't force you to add anything in the cxx
>>>>> >>> file. You can pretty much not know what that macro does and you're
>>>>> >>> okay. Not so with this macro. Also hiding constructor/destructor is
>>>>> >>> really weird to me. Why would you? I don't think I am thrilled by
>>>>> >>> having to implement function definitions without seeing their
>>>>> >>> declarations in the header. None of the existing macros do that, not
>>>>> >>> even in Qt, as far as I know. Readability of code is far more
>>>>> >>> important that saving typing a few more lines, IMHO.
>>>>> >>>
>>>>> >>I can see your point with the contructor/desctructor. Even with them
>>>>> >>removed I still think this macro would be very useful.
>>>>> >>
>>>>> >>Marcus
>>>>> >>_______________________________________________
>>>>> >>Powered by www.kitware.com
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>>>>> >
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>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Cory Quammen
>>>>> Research Associate
>>>>> Department of Computer Science
>>>>> The University of North Carolina at Chapel Hill
>>>>> _______________________________________________
>>>>> Powered by www.kitware.com
>>>>>
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>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> | Aashish Chaudhary
>>>> | R&D Engineer
>>>> | Kitware Inc.
>>>> | www.kitware.com
>>>>
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