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Re: would you consider this function const?

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>>
>> One of the issues that spurred this question (related to my func1 in the
>> original post) is the following. I have a 3D mesh composed of
>> Volumes/Faces/Edges/Vertices. So, I have a Volume, Face, Edge, and
>> Vertex class, each derived from a base Topology class. The mesh is
>> consistent, so given a particular instance of one of the classes, there
>> are functions that return geometry information such as connectivity. In
>> particular, each class has a virtual function (declared as pure virtual
>> at the base Topology class)
>>
>> virtual void GetVolumes(std::set<Volume*> volumes);
>
> That doesn't look right. Did you lose the ampersand before the argument
> name?
>

Yes, it should be
	
	virtual void GetVolumes(std::set<Volume*>& volumes);


>>
>> that returns a list of pointers to the volumes associated with the
>> entity. I want to make this function 'const' since it does not change
>> the element. For a Face, Edge, and Vertex, this poses no problem.
>> However, for a volume instance, the function should return a pointer to
>> just itself, so if GetVolumes is const, then I have
>>
>> void Volume::GetVolumes(std::set<Volume*> volumes) const
>> {
>> volumes.clear();
>> volumes.insert(const_cast<Volume*>(this));
>> }
>>
>> I do not see how to have the GetVolumes function const without the use
>> of const_cast in the Volume::GetVolumes function. Is there a more
>> intelligent way to get the same result?
>
> What happens if you change the type of the argument to
>
> std::set<const Volume*>
>
> ? If it's a set of constant volumes, that's what the type should
> express. If you find it difficult to type, use a typedef *or* introduce
> some kind of 'Volume proxy' and keep that instead of the pointer to Volume.

I will have to look at whether I can do that or not.  My guess is that, 
for the most part, I will need non-const Volume*'s.  It's a huge code 
base, so a change like that could ripple to a lot of places.

John

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would you consider this function const? john <gh14tq5@yahoo.com> - 2011-12-14 10:17 -0500
  Re: would you consider this function const? Victor Bazarov <v.bazarov@comcast.invalid> - 2011-12-14 11:19 -0500
    Re: would you consider this function const? john <gh14tq5@yahoo.com> - 2011-12-15 08:10 -0500
      Re: would you consider this function const? Victor Bazarov <v.bazarov@comcast.invalid> - 2011-12-15 08:21 -0500
        Re: would you consider this function const? john <gh14tq5@yahoo.com> - 2011-12-15 08:44 -0500
          Re: would you consider this function const? Leigh Johnston <leigh@i42.co.uk> - 2011-12-15 14:07 +0000
            Re: would you consider this function const? Leigh Johnston <leigh@i42.co.uk> - 2011-12-15 14:14 +0000
          Re: would you consider this function const? Victor Bazarov <v.bazarov@comcast.invalid> - 2011-12-15 09:11 -0500
            Re: would you consider this function const? john <gh14tq5@yahoo.com> - 2011-12-15 09:30 -0500
              Re: would you consider this function const? Victor Bazarov <v.bazarov@comcast.invalid> - 2011-12-15 10:06 -0500
                Re: would you consider this function const? john <gh14tq5@yahoo.com> - 2011-12-15 12:42 -0500
                Re: would you consider this function const? Victor Bazarov <v.bazarov@comcast.invalid> - 2011-12-15 13:32 -0500
    Re: would you consider this function const? yatremblay@bel1lin202.(none) (Yannick Tremblay) - 2011-12-19 18:16 +0000
      Re: would you consider this function const? Tobias Müller <troplin@bluewin.ch> - 2011-12-19 19:05 +0000
        Re: would you consider this function const? Joshua Maurice <joshuamaurice@gmail.com> - 2011-12-19 14:36 -0800
          Re: would you consider this function const? Tobias Müller <troplin@bluewin.ch> - 2011-12-20 06:28 +0000
            Re: would you consider this function const? Joshua Maurice <joshuamaurice@gmail.com> - 2011-12-19 23:48 -0800

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