Explicit template implementation: MSVC and GCC

I am trying to deal with namespaces and patterns in C ++. I can get the following code to compile in MSVC (no warnings or errors), but I was not lucky with various permutations with CYGWIN / GCC. Any help would be appreciated.

In the header file, I declare a template subclass as follows:

#include <gdal.h>
namespace sfms {

template <class _type, GDALDataType _gdal> class SmfsGrid_Typed : public SfmsGrid_Base {
public:
  SmfsGrid_Typed();
  SmfsGrid_Typed(const SmfsGrid_Typed<_type, _gdal> *toCopy);
  SmfsGrid_Typed(std::string filename);
  virtual ~SmfsGrid_Typed();
  virtual bool OpenRead();
  virtual bool OpenWrite();

protected:
  _type m_nodata_value;

  virtual SfmsGrid_Base *New() const;
  virtual SfmsGrid_Base *New(SfmsGrid_Base *toCopy) const;
  virtual void initCopy(SfmsGrid_Base *copy) const;
};

template SmfsGrid_Typed<double, GDT_Float64>;
template SmfsGrid_Typed<float, GDT_Float32>;
template SmfsGrid_Typed<int, GDT_Int32>;

typedef SmfsGrid_Typed<double, GDT_Float64> SmfsGrid_Double;
typedef SmfsGrid_Typed<float, GDT_Float32> SmfsGrid_Float;
typedef SmfsGrid_Typed<int, GDT_Int32> SmfsGrid_Int;
}

In the source file, I create a custom template class as follows:

void hi_there() {
//...
sfms::SmfsGrid_Typed<int, GDT_Int32> *grid = new sfms::SmfsGrid_Typed<int, GDT_Int32>(filey);
//...
sfms::SmfsGrid_Int *grid2 = new sfms::SmfsGrid_Int(filey);
//...
}

GDALDataType is an enumeration, but it does not seem to be a problem.

I tried declaring the class inside and outside the namespace, without success.

The source file containing the implementations for the templates is compiled with both compilers.

I tried to remove the explicit template creation and include the corresponding C ++ source file, also without joy.

'template', 'typename' 'typedef' ( def'n ) , GCC, :

error: 'SmfsGrid_Typed' is not a member of 'sfms'

!:) , MSVC GCC .

!