https://svn.lrde.epita.fr/svn/oln/trunk/static Index: ChangeLog from Roland Levillain <roland@lrde.epita.fr> Improve the Point2d and Point3d concepts in mini-oln. * samples/mini-oln/concept-c++/mini-oln.cc (concepts::Point2d, concepts::Point3d): Enrich them. (concept_map Point2d<oln::point2d>) (concept_map Point3d<oln::point3d>): Adjust. (oln::point2d::coord_type, oln::point3d::coord_type): New typedefs. (oln::point2d::row, oln::point2d::col) (oln::point3d::row, oln::point3d::col, oln::point3d::sli): Use it. mini-oln.cc | 46 +++++++++++++++++++++++++++++++++++++--------- 1 file changed, 37 insertions(+), 9 deletions(-) Index: samples/mini-oln/concept-c++/mini-oln.cc --- samples/mini-oln/concept-c++/mini-oln.cc (revision 731) +++ samples/mini-oln/concept-c++/mini-oln.cc (working copy) @@ -61,8 +61,27 @@ namespace concepts { - concept Point2d<typename P> {}; - concept Point3d<typename P> {}; + // These concepts are not automatic (i.e., prefixed with `auto'), + // since we cannot rely on type signatures for them. For instance, + // using only structural conformance, oln::point3d could be a model + // of concepts::Point2d! + concept Point2d<typename P> + { + typename coord_type; + // For simplicity purpose, the canonical model of + // concepts::Point2d -- oln::point2d -- does not expose its + // interface through methods (that's bad OO software engineering + // practice, but hey, we're just prototyping here). Therefore we + // cannot express sigatures on row and col accesses, since C++0x + // concepts forbid attribute (member) signatures. + }; + + concept Point3d<typename P> + { + typename coord_type; + // Same remark as above for concepts::Point2d regarding member + // signatures. + }; auto concept Image<typename I> { @@ -110,22 +129,31 @@ struct point2d : public Point<point2d> { - int row; - int col; + typedef int coord_type; + coord_type row; + coord_type col; }; struct point3d : public Point<point2d> { - int row; - int col; - int sli; + typedef int coord_type; + coord_type row; + coord_type col; + coord_type sli; }; } namespace concepts { - concept_map Point2d<oln::point2d> {}; - concept_map Point3d<oln::point3d> {}; + concept_map Point2d<oln::point2d> + { + typedef oln::point2d::coord_type coord_type; + }; + + concept_map Point3d<oln::point3d> + { + typedef oln::point2d::coord_type coord_type; + }; }