template class błąd z konstruktorem

// Wycięty do najważniejszych części 
template<typename T>
// shape.hpp:
class shape
{
public:

  shape(const sf::ConvexShape&;
  shape(const sf::RectangleShape&);
  shape(const sf::CircleShape&);
 ~shape() = default;

private:
  T       visual;
};
// shape.cpp:

 template<typename T>
 shape<T>::shape(const sf::CircleShape& shape)
 {

    visual = shape;
 // (...)
 }
 template<typename T>
 shape<T>::shape(const sf::ConvexShape& shape)
 {
  visual = shape;
// (...)

 }
 template<typename T>
 shape<T>::shape(const sf::RectangleShape& shape)
 {
      visual = shape;
  // (...)

 }
// main.cpp
int main()
{
sf::CircleShape circ;
shape<sf::CircleShape> circle(circ);

sf::RectangleShape ground;
shape<sf::RectangleShape> rect(ground);
}

undefined reference to `shape<sf::CircleShape>::shape(sf::CircleShape const&)'|
undefined reference to `shape<sf::RectangleShape>::shape(sf::RectangleShape const&)'|

// main.cpp
template class shape<sf::CircleShape>;
template class shape<sf::RectangleShape>;

 no match for 'operator=' in '((shape<sf::RectangleShape>*)this)->shape<sf::RectangleShape>::visual = shape'|
 candidate is:
 sf::RectangleShape& sf::RectangleShape::operator=(const sf::RectangleShape&)|
  no known conversion for argument 1 from 'const sf::CircleShape' to 'const sf::RectangleShape&'|

template<typename T> class shape
  {
   private:
   T visual;
   public:
   shape(const T visual&):visual(visual) {}
  };