boost/geometry/core/tag.hpp
// Boost.Geometry (aka GGL, Generic Geometry Library) // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands. // Copyright (c) 2008-2012 Bruno Lalande, Paris, France. // Copyright (c) 2009-2012 Mateusz Loskot, London, UK. // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands. // Use, modification and distribution is subject to the Boost Software License, // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #ifndef BOOST_GEOMETRY_CORE_TAG_HPP #define BOOST_GEOMETRY_CORE_TAG_HPP #include <boost/mpl/assert.hpp> #include <boost/type_traits/remove_const.hpp> #include <boost/geometry/core/tags.hpp> namespace boost { namespace geometry { namespace traits { /*! \brief Traits class to attach a tag to a geometry \details All geometries should implement a traits::tag<G>::type metafunction to indicate their own geometry type. \ingroup traits \par Geometries: - all geometries \par Specializations should provide: - typedef XXX_tag type; (point_tag, box_tag, ...) \tparam Geometry geometry */ template <typename Geometry, typename Enable = void> struct tag { typedef void type; }; } // namespace traits /*! \brief \brief_meta{type, tag, \meta_geometry_type} \details With Boost.Geometry, tags are the driving force of the tag dispatching mechanism. The tag metafunction is therefore used in every free function. \tparam Geometry \tparam_geometry \ingroup core \qbk{[include reference/core/tag.qbk]} */ template <typename Geometry> struct tag { typedef typename traits::tag < typename boost::remove_const<Geometry>::type >::type type; }; }} // namespace boost::geometry #endif // BOOST_GEOMETRY_CORE_TAG_HPP