*** pnm_tags.hpp	2010-03-02 09:54:05.000000000 +0100
--- /usr/local/include/boost/gil/extension/io_new/pnm_tags.hpp	2010-03-02 09:25:18.167817981 +0100
***************
*** 39,44 ****
--- 39,51 ----
      static const type _color_bin = 6; // sRGB color binary encoding
  };
  
+ const pnm_image_type::type pnm_image_type::_mono_asc;
+ const pnm_image_type::type pnm_image_type::_gray_asc;
+ const pnm_image_type::type pnm_image_type::_color_asc;
+ const pnm_image_type::type pnm_image_type::_mono_bin;
+ const pnm_image_type::type pnm_image_type::_gray_bin;
+ const pnm_image_type::type pnm_image_type::_color_bin;
+ 
  /// Defines type for image width property.
  struct pnm_image_width : property_base< uint32_t > {};