Boost C++ Libraries

boost/geometry/core/tags.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.

// This file was modified by Oracle on 2014-2020.
// Modifications copyright (c) 2014-2020 Oracle and/or its affiliates.
// Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle

// 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_TAGS_HPP
#define BOOST_GEOMETRY_CORE_TAGS_HPP


namespace boost { namespace geometry
{

// Tags defining strategies linked to coordinate systems

/// Tag used for undefined coordinate system
struct cs_undefined_tag {};

/// Tag used for casting spherical/geographic coordinate systems
struct spherical_tag {};


/// Tag indicating Cartesian coordinate system family (cartesian,epsg)
struct cartesian_tag {};

/// Tag indicating Spherical polar coordinate system family
struct spherical_polar_tag : spherical_tag {};

/// Tag indicating Spherical equatorial coordinate system family
struct spherical_equatorial_tag : spherical_tag {};

/// Tag indicating Geographic coordinate system family (geographic)
struct geographic_tag : spherical_tag {};


// Tags defining coordinate systems reference models

/// For reference spheroid defining parameters of geographical coordinate system
struct srs_spheroid_tag {};

/// For reference sphere defining parameters of spherical coordinate system
struct srs_sphere_tag : srs_spheroid_tag {};


// Tags defining tag hierarchy

/// For single-geometries (point, linestring, polygon, box, ring, segment)
struct single_tag {};


/// For multiple-geometries (multi_point, multi_linestring, multi_polygon)
struct multi_tag {};

/// For point-like types (point, multi_point)
struct pointlike_tag {};

/// For linear types (linestring, multi-linestring, segment)
struct linear_tag {};

// Subset of linear types (polygon, multi_polygon)
struct polylinear_tag : linear_tag {};

/// For areal types (polygon, multi_polygon, box, ring)
struct areal_tag {};

// Subset of areal types (polygon, multi_polygon, ring)
struct polygonal_tag : areal_tag {};

/// For volume types (also box (?), polyhedron)
struct volumetric_tag {};


// Tags defining geometry types


/// "default" tag
struct geometry_not_recognized_tag {};

/// OGC Point identifying tag
struct point_tag : single_tag, pointlike_tag {};

/// OGC Linestring identifying tag
struct linestring_tag : single_tag, polylinear_tag {};

/// OGC Polygon identifying tag
struct polygon_tag : single_tag, polygonal_tag {};

/// Convenience (linear) ring identifying tag
struct ring_tag : single_tag, polygonal_tag {};

/// Convenience 2D or 3D box (mbr / aabb) identifying tag
struct box_tag : single_tag, areal_tag {};

/// Convenience segment (2-points) identifying tag
struct segment_tag : single_tag, linear_tag {};


/// OGC Multi point identifying tag
struct multi_point_tag : multi_tag, pointlike_tag  {};

/// OGC Multi linestring identifying tag
struct multi_linestring_tag : multi_tag, polylinear_tag {};

/// OGC Multi polygon identifying tag
struct multi_polygon_tag : multi_tag, polygonal_tag {};

/// OGC Geometry Collection identifying tag
struct geometry_collection_tag : multi_tag {};


/*!
\brief Meta-function to get for a tag of a multi-geometry
    the tag of the corresponding single-geometry
*/
template <typename Tag>
struct single_tag_of
{};

#ifndef DOXYGEN_NO_DETAIL

template <>
struct single_tag_of<multi_point_tag>
{
    typedef point_tag type;
};

template <>
struct single_tag_of<multi_linestring_tag>
{
    typedef linestring_tag type;
};

template <>
struct single_tag_of<multi_polygon_tag>
{
    typedef polygon_tag type;
};

#endif


}} // namespace boost::geometry

#endif // BOOST_GEOMETRY_CORE_TAGS_HPP