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Pure virtual function of template class (undefined reference)

Nebekau (4)
ishape.h
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template < typename T >
class IShape {

public:

    IShape() {}

    virtual void move(const T&, const T& = 0, const T& = 0) = 0;

    virtual ~IShape() {}
};


ishape_2d.h
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#include "ishape.h"

template <typename T>
class IShape_2D : public IShape< T> {
public:

    IShape_2D() {}

    virtual T perimeter() const = 0;

    virtual ~IShape_2D() {}
};


polygon.h
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#include "ishape_2d.h"

template< typename T>
class Polygon : public IShape_2D< T>
{

public:

    Polygon() {}

    ~Polygon() {}

    void move(const T&, const T&, const T&);
}

template< typename T>
void Polygon< T >::move(const T& x, const T& y, const T& z)
{
     
}

template< typename T >
T Polygon< T >::perimeter() const
{
     return 0;
}


main.cpp
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#include "polygon.h"

int main()
{
    Polygon<float> pentagon;

    return 0;
}


An error keeps coming

debug/main.o:main.cpp:(.rdata$_ZTVN3geo9IShape_2DIfEE[vtable for IShape_2D<float>]+0xc): undefined reference to `IShape<float>::move(float const&, float const&, float const&)'
debug/main.o:main.cpp:(.rdata$_ZTVN3geo6IShapeIfEE[vtable for IShape<float>]+0xc): undefined reference to `IShape<float>::move(float const&, float const&, float const&)'
collect2: ld returned 1 exit status

The process "C:\mingw\bin\mingw32-make.exe" exited with code 2.


any ideas?
closed account (o1vk4iN6)
Is it defined in the header file ? Since it's a template class the implementation needs to be visible in the header file, it can't be in the source as it has to be compiled dependent on the type.
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