Re: VC++ 2005 Express - LNK2001 with static var

My C++ is pretty rusty so this might just be a stupid oversite but,

I'm trying to build a DLL with the following class:

//************** SoundObject.h ***************
#ifndef SOUNDOBJECT_H
#define SOUNDOBJECT_H

#define DllExport __declspec(dllexport)

typedef double SoundChunk; // This type is used by most objects in the
SoundTools library
namespace SoundTools
{
   class SoundObject
   {
   private:
       static SoundChunk _sampleRate; // default sample rate
   protected:
       SoundObject();
   public:
       static DllExport SoundChunk GetSampleRate(void);
       static DllExport void SetSampleRate(SoundChunk r);
   };
}
#endif

//************** SoundObject.cpp ***************

#include "SoundObject.h"
namespace SoundTools
{
   SoundObject::SoundObject()
   {
       SoundObject::_sampleRate = 44100.0;
   }
   SoundChunk SoundObject::GetSampleRate()
   {
       return _sampleRate;
   }
   void SoundObject::SetSampleRate(SoundChunk r)
   {
       if(r > 0.0)
           _sampleRate = r;
   }
}

//********************************************

When I try to build the DLL I get this linker error:

SoundObject.obj : error LNK2001: unresolved external symbol "private:
static double SoundTools::SoundObject::_sampleRate"
(?_sampleRate@SoundObject@SoundTools@@0NA)

I tried some different things including declaring _sampleRate as extern
and using explicit declarations in the *.cpp file. Not sure what I'm doing
wrong.