Re: Problem with static variable in template class

In utility.hpp I have:

namespace utility
{

template <class T, double (T::*F)(double) const>
class Display
{
private:
        static double resolution;
        static double margin;

public:
        static void computePlot(stringstream& ss, const T& t, const
ClosedInterval& interval);

};
}

In utility.cpp:

#include <utility.hpp>
namespace utility
{

template <class T, double (T::*F)(double) const>
double Display<T,F>::resolution = 0.025;

template <class T, double (T::*F)(double) const>
double Display<T,F>::margin = 5;

}

Then I have another cpp file in which I'm including utility.hpp and
calling the computePlot function using:

utility::Display<EnvelopePiece, &EnvelopePiece::f>::computePlot( ss,
*this, interval );

(the *this because I'm inside a member function of the EnvelopePiece
class when I'm calling computePlot)

However when compiling I get:
1>envelope.obj : error LNK2001: unresolved external symbol "private:
static double utility::Display<class EnvelopePiece,&public: double
__thiscall EnvelopePiece::f(double)const >::resolution" (?resolution@?
$Display@VEnvelopePiece@@$1?f@1@QBENN@Z@utility@@0NA)

Like if the static variables were not declared.
But isn't double Display<T,F>::resolution the proper way to declare
the "generic" template static variable, that I can then specialize if
I want to?

Thanks

StephQ