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Redefined name?

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Join Date: Feb 2008

Posts: 628

Reputation: daviddoria is a jewel in the rough

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daviddoria daviddoria is offline

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Redefined name?

Oct 9th, 2009

I am looking at some open source code and I am a bit confused. There is an Allocator class:

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class Allocator{

Then in another class, they have:

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class Octree{
public:
	static Allocator<OctNode> Allocator;
class Octree{
public:
	static Allocator<OctNode> Allocator;

When trying to compile, I am getting:

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error: declaration of 'Allocator<OctNode<NodeData, Real> > OctNode<NodeData, Real>::Allocator'
error: changes meaning of 'Allocator' from 'class Allocator<OctNode<NodeData, Real> >'
error: declaration of 'Allocator<OctNode<NodeData, Real> > OctNode<NodeData, Real>::Allocator'
error: changes meaning of 'Allocator' from 'class Allocator<OctNode<NodeData, Real> >'

which makes sense, because it is like they are trying to make a variable named Allocator of type Allocator, which doesn't make sense. However, this is a pretty well known project so surely it compiles for most people - I am wondering if anyone can tell me if I am interpreting this correctly and why it may compile for others and what I can do to fix it?

Thanks,

Dave

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Join Date: Feb 2008

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daviddoria daviddoria is offline

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Oct 12th, 2009

Any ideas?

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Join Date: Sep 2009

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Reputation: dkalita will become famous soon enough

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dkalita

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Oct 12th, 2009

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error: changes meaning of 'Allocator' from 'class Allocator<OctNode<NodeData, Real> >'

what is the OctNode class. If it's a template class u have to write it as so

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class Octree{
public:
	static Allocator<OctNode<NodeData, Real>> Allocator;
class Octree{
public:
	static Allocator<OctNode<NodeData, Real>> Allocator;

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Join Date: Feb 2008

Posts: 628

Reputation: daviddoria is a jewel in the rough

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daviddoria daviddoria is offline

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Oct 12th, 2009

Hm I tried that - didn't seem to work. Here is a super simplified version that produces the same error:

http://www.rpi.edu/~doriad/Daniweb/octree/

I still think the problem is simply that they tried to re-use a name? Is this the case?

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Join Date: Nov 2008

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Reputation: StuXYZ is a glorious beacon of light

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StuXYZ

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Oct 12th, 2009

Yes the problem is name reuse. The code compiles fine if you cahgne the name OR you put allocator in a namespace e.g

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namespace X
{
template<class T>
class Allocator{
 
public:
  Allocator(void){}
 
};
 
}
 
template<class NodeData,class Real=float>
class OctNode
{
private:
 
public:
  static  X::Allocator<OctNode<NodeData,Real> > Allocator;
};
namespace X
{
template<class T>
class Allocator{
  
public:
  Allocator(void){}
  
};

}

template<class NodeData,class Real=float>
class OctNode
{
private:

public:
  static  X::Allocator<OctNode<NodeData,Real> > Allocator;
};