Added empty_input_exception and applied for distance, length, area, perimeter

Removed exception for convex_hull because that can be handled (for now) by leaving output empty. To be decided what is the definitive (additional, optional) behaviour.

[SVN r76514]

include/boost/geometry/algorithms/area.hpp

@@ -19,7 +19,6 @@
 #include <boost/range/functions.hpp>
 #include <boost/range/metafunctions.hpp>
 
-
 #include <boost/geometry/core/closure.hpp>
 #include <boost/geometry/core/exterior_ring.hpp>
 #include <boost/geometry/core/interior_rings.hpp>
@@ -30,6 +29,7 @@
 
 #include <boost/geometry/algorithms/detail/calculate_null.hpp>
 #include <boost/geometry/algorithms/detail/calculate_sum.hpp>
+#include <boost/geometry/algorithms/detail/throw_on_empty_input.hpp>
 
 #include <boost/geometry/strategies/area.hpp>
 #include <boost/geometry/strategies/default_area_result.hpp>
@@ -241,6 +241,8 @@ inline typename default_area_result<Geometry>::type area(Geometry const& geometr
             point_type
         >::type strategy_type;
 
+    detail::throw_on_empty_input(geometry);
+        
     return dispatch::area
         <
             Geometry
@@ -277,6 +279,8 @@ inline typename Strategy::return_type area(
 {
     concept::check<Geometry const>();
 
+    detail::throw_on_empty_input(geometry);
+    
     return dispatch::area
         <
             Geometry,

include/boost/geometry/algorithms/convex_hull.hpp

@@ -35,33 +35,6 @@
 namespace boost { namespace geometry
 {
 
-#if ! defined(BOOST_GEOMETRY_CONVEX_HULL_NO_THROW)
-
-/*!
-\brief Convex Hull Exception
-\ingroup convex_hull
-\details The convex_hull_exception is thrown if the free convex hull function is called with
-    geometries for which the hull cannot be calculated. For example: a linestring
-    without points, a polygon without points, an empty multi-geometry.
-\qbk{
-[heading See also]
-\* [link geometry.reference.algorithms.convex_hull the convex_hull function]
-}
-
- */
-class convex_hull_exception : public geometry::exception
-{
-public:
-
-    inline convex_hull_exception() {}
-
-    virtual char const* what() const throw()
-    {
-        return "Boost.Geometry Convex Hull calculation exception";
-    }
-};
-
-#endif
 
 #ifndef DOXYGEN_NO_DETAIL
 namespace detail { namespace convex_hull
@@ -204,9 +177,7 @@ inline void convex_hull(Geometry const& geometry,
 
     if (geometry::num_points(geometry) == 0)
     {
-#if ! defined(BOOST_GEOMETRY_CONVEX_HULL_NO_THROW)
-        throw convex_hull_exception();
-#endif
+        // Leave output empty
         return;
     }
 

include/boost/geometry/algorithms/detail/throw_on_empty_input.hpp

@@ -0,0 +1,43 @@
+// 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.
+
+// 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_ALGORITHMS_DETAIL_THROW_ON_EMPTY_INPUT_HPP
+#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_THROW_ON_EMPTY_INPUT_HPP
+
+#include <boost/geometry/core/exception.hpp>
+#include <boost/geometry/algorithms/num_points.hpp>
+
+namespace boost { namespace geometry
+{
+
+#ifndef DOXYGEN_NO_DETAIL
+namespace detail
+{
+
+template <typename Geometry>
+inline void throw_on_empty_input(Geometry const& geometry)
+{
+#if ! defined(BOOST_GEOMETRY_EMPTY_INPUT_NO_THROW)
+    if (geometry::num_points(geometry) == 0)
+    {
+        throw empty_input_exception();
+    }
+#endif
+}
+
+} // namespace detail
+#endif // DOXYGEN_NO_DETAIL
+
+
+}} // namespace boost::geometry
+
+
+#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_THROW_ON_EMPTY_INPUT_HPP
+

include/boost/geometry/algorithms/distance.hpp

@@ -25,6 +25,7 @@
 #include <boost/geometry/core/tag_cast.hpp>
 
 #include <boost/geometry/algorithms/not_implemented.hpp>
+#include <boost/geometry/algorithms/detail/throw_on_empty_input.hpp>
 
 #include <boost/geometry/geometries/segment.hpp>
 #include <boost/geometry/geometries/concepts/check.hpp>
@@ -549,6 +550,9 @@ inline typename strategy::distance::services::return_type<Strategy>::type distan
 {
     concept::check<Geometry1 const>();
     concept::check<Geometry2 const>();
+    
+    detail::throw_on_empty_input(geometry1);
+    detail::throw_on_empty_input(geometry2);
 
     return dispatch::distance
                <

include/boost/geometry/algorithms/length.hpp

@@ -28,6 +28,7 @@
 
 #include <boost/geometry/algorithms/assign.hpp>
 #include <boost/geometry/algorithms/detail/calculate_null.hpp>
+#include <boost/geometry/algorithms/detail/throw_on_empty_input.hpp>
 #include <boost/geometry/views/closeable_view.hpp>
 #include <boost/geometry/strategies/distance.hpp>
 #include <boost/geometry/strategies/default_length_result.hpp>
@@ -151,6 +152,8 @@ inline typename default_length_result<Geometry>::type length(
 {
     concept::check<Geometry const>();
 
+    detail::throw_on_empty_input(geometry);
+
     typedef typename strategy::distance::services::default_strategy
         <
             point_tag, typename point_type<Geometry>::type
@@ -185,6 +188,8 @@ inline typename default_length_result<Geometry>::type length(
 {
     concept::check<Geometry const>();
 
+    detail::throw_on_empty_input(geometry);
+    
     return dispatch::length
         <
             typename tag<Geometry>::type,

include/boost/geometry/algorithms/perimeter.hpp

@@ -22,6 +22,7 @@
 #include <boost/geometry/algorithms/length.hpp>
 #include <boost/geometry/algorithms/detail/calculate_null.hpp>
 #include <boost/geometry/algorithms/detail/calculate_sum.hpp>
+#include <boost/geometry/algorithms/detail/throw_on_empty_input.hpp>
 
 
 namespace boost { namespace geometry
@@ -97,6 +98,8 @@ inline typename default_length_result<Geometry>::type perimeter(
             point_tag, point_type
         >::type strategy_type;
 
+    detail::throw_on_empty_input(geometry);
+        
     return dispatch::perimeter
         <
             typename tag<Geometry>::type,
@@ -125,6 +128,8 @@ inline typename default_length_result<Geometry>::type perimeter(
 {
     concept::check<Geometry const>();
 
+    detail::throw_on_empty_input(geometry);
+    
     return dispatch::perimeter
         <
             typename tag<Geometry>::type,

include/boost/geometry/core/exception.hpp

@@ -29,6 +29,32 @@ class exception : public std::exception
 {};
 
 
+/*!
+\brief Empty Input Exception
+\ingroup core
+\details The empty_input_exception is thrown if free functions, e.g. distance,
+    are called with empty geometries, e.g. a linestring
+    without points, a polygon without points, an empty multi-geometry.
+\qbk{
+[heading See also]
+\* [link geometry.reference.algorithms.area the area function]
+\* [link geometry.reference.algorithms.distance the distance function]
+\* [link geometry.reference.algorithms.length the length function]
+}
+ */
+class empty_input_exception : public geometry::exception
+{
+public:
+
+    inline empty_input_exception() {}
+
+    virtual char const* what() const throw()
+    {
+        return "Boost.Geometry Empty-Input exception";
+    }
+};
+
+
 }} // namespace boost::geometry
 
 #endif // BOOST_GEOMETRY_CORE_EXCEPTION_HPP

include/boost/geometry/multi/algorithms/distance.hpp

@@ -23,6 +23,7 @@
 #include <boost/geometry/multi/core/point_type.hpp>
 
 #include <boost/geometry/algorithms/distance.hpp>
+#include <boost/geometry/multi/algorithms/num_points.hpp>
 #include <boost/geometry/util/select_coordinate_type.hpp>
 
 
@@ -49,12 +50,12 @@ struct distance_single_to_multi
                 MultiGeometry const& multi,
                 Strategy const& strategy)
     {
+        return_type mindist = return_type();
         bool first = true;
-        return_type mindist;
 
         for(typename range_iterator<MultiGeometry const>::type it = boost::begin(multi);
                 it != boost::end(multi);
-                ++it)
+                ++it, first = false)
         {
             return_type dist = dispatch::distance
                 <
@@ -67,7 +68,6 @@ struct distance_single_to_multi
             {
                 mindist = dist;
             }
-            first = false;
         }
 
         return mindist;
@@ -88,12 +88,12 @@ struct distance_multi_to_multi
     static inline return_type apply(Multi1 const& multi1,
                 Multi2 const& multi2, Strategy const& strategy)
     {
+        return_type mindist = return_type();
         bool first = true;
-        return_type mindist;
 
         for(typename range_iterator<Multi1 const>::type it = boost::begin(multi1);
                 it != boost::end(multi1);
-                ++it)
+                ++it, first = false)
         {
             return_type dist = distance_single_to_multi
                 <
@@ -105,7 +105,6 @@ struct distance_multi_to_multi
             {
                 mindist = dist;
             }
-            first = false;
         }
 
         return mindist;