[strategies][distance] add class to convert a distance result from comparable to regular distance result if needed;

add implementation of this for cartesian coordinates (applies sqrt);

include/boost/geometry/strategies/cartesian/distance_comparable_to_regular.hpp

@@ -0,0 +1,106 @@
+// Boost.Geometry (aka GGL, Generic Geometry Library)
+
+// Copyright (c) 2014, Oracle and/or its affiliates.
+
+// Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
+
+// Licensed under the Boost Software License version 1.0.
+// http://www.boost.org/users/license.html
+
+#ifndef BOOST_GEOMETRY_STRATEGIES_CARTESIAN_DISTANCE_COMPARABLE_TO_REGULAR_HPP
+#define BOOST_GEOMETRY_STRATEGIES_CARTESIAN_DISTANCE_COMPARABLE_TO_REGULAR_HPP
+
+
+#include <cmath>
+#include <boost/geometry/strategies/distance_comparable_to_regular.hpp>
+#include <boost/geometry/core/point_type.hpp>
+
+namespace boost { namespace geometry
+{
+
+namespace strategy { namespace distance
+{
+
+
+
+#ifndef DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
+namespace services
+{
+
+
+template
+<
+    typename ComparableStrategy,
+    typename Strategy,
+    typename Geometry1,
+    typename Geometry2
+>
+struct comparable_to_regular
+    <
+        ComparableStrategy, Strategy,
+        Geometry1, Geometry2,
+        cartesian_tag, cartesian_tag
+    >
+{
+    typedef typename return_type
+        <
+            Strategy,
+            typename point_type<Geometry1>::type,
+            typename point_type<Geometry2>::type
+        >::type calculation_type;
+
+    typedef typename return_type
+        <
+            ComparableStrategy,
+            typename point_type<Geometry1>::type,
+            typename point_type<Geometry2>::type
+        >::type comparable_calculation_type;
+
+    static inline calculation_type apply(comparable_calculation_type const& cd)
+    {
+        return sqrt( boost::numeric_cast<calculation_type>(cd) );
+    }
+};
+
+
+
+template <typename ComparableStrategy, typename Geometry1, typename Geometry2>
+struct comparable_to_regular
+    <
+        ComparableStrategy,
+        ComparableStrategy,
+        Geometry1,
+        Geometry2,
+        cartesian_tag,
+        cartesian_tag
+    >
+{
+    typedef typename return_type
+        <
+            ComparableStrategy,
+            typename point_type<Geometry1>::type,
+            typename point_type<Geometry2>::type
+        >::type comparable_calculation_type;
+
+    static inline comparable_calculation_type
+    apply(comparable_calculation_type const& cd)
+    {
+        return cd;
+    }
+};
+
+
+
+
+
+
+
+} // namespace services
+#endif // DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
+
+
+}} // namespace strategy::distance
+
+}} // namespace boost::geometry
+
+#endif // BOOST_GEOMETRY_STRATEGIES_CARTESIAN_DISTANCE_COMPARABLE_TO_REGULAR_HPP

include/boost/geometry/strategies/distance_comparable_to_regular.hpp

@@ -0,0 +1,53 @@
+// Boost.Geometry (aka GGL, Generic Geometry Library)
+
+// Copyright (c) 2014, Oracle and/or its affiliates.
+
+// Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
+
+// Licensed under the Boost Software License version 1.0.
+// http://www.boost.org/users/license.html
+
+#ifndef BOOST_GEOMETRY_STRATEGIES_DISTANCE_COMPARABLE_TO_REGULAR_HPP
+#define BOOST_GEOMETRY_STRATEGIES_DISTANCE_COMPARABLE_TO_REGULAR_HPP
+
+#include <boost/geometry/core/tags.hpp>
+#include <boost/geometry/core/cs.hpp>
+#include <boost/geometry/algorithms/not_implemented.hpp>
+
+
+namespace boost { namespace geometry
+{
+
+namespace strategy { namespace distance
+{
+
+
+
+#ifndef DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
+namespace services
+{
+
+
+template
+<
+    typename ComparableStrategy,
+    typename Strategy,
+    typename Geometry1,
+    typename Geometry2,
+    typename CsTag1 = typename cs_tag<Geometry1>::type,
+    typename CsTag2 = typename cs_tag<Geometry2>::type
+>
+struct comparable_to_regular
+    : geometry::not_implemented<CsTag1, CsTag2>
+{};
+
+
+} // namespace services
+#endif // DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
+
+
+}} // namespace strategy::distance
+
+}} // namespace boost::geometry
+
+#endif // BOOST_GEOMETRY_STRATEGIES_DISTANCE_COMPARABLE_TO_REGULAR_HPP