Thread: Template trouble

I have the following class

Code:

// ZLine.h

#ifndef _ZLINE_H
#define _ZLINE_H

namespace Z_GLC {

template<typename T> class ZLine
{
    public:
        ZLine(T x1, T y1, T x2, T y2);

       double DistanceFromPoint(T x, T y);
    
    private:
       T a, b, c;
};

} // namespace

#endif

Code:

// ZLine.cpp

#include "ZLine.h"'

namespace Z_GLC {

template<typename T> ZLine<T>::ZLine(T x1, T y1, T x2, T y2)
{
    // implementation
}

template<typename T> double ZLine<T>::DistanceFromPoint(T x, T y)
{
    // implementation
}

} // namespace

When I try to use the class I get link errors. How to deal with this issue?