Add if constexpr macro and replace condition macro.

Author: awulkiew

include/boost/geometry/algorithms/densify.hpp

@@ -1,7 +1,8 @@
 // Boost.Geometry
 
-// Copyright (c) 2017-2021, Oracle and/or its affiliates.
+// Copyright (c) 2023 Adam Wulkiewicz, Lodz, Poland.
 
+// Copyright (c) 2017-2021, Oracle and/or its affiliates.
 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
 
 // Licensed under the Boost Software License version 1.0.
@@ -33,7 +34,7 @@
 #include <boost/geometry/strategies/densify/geographic.hpp>
 #include <boost/geometry/strategies/densify/spherical.hpp>
 #include <boost/geometry/strategies/detail.hpp>
-#include <boost/geometry/util/condition.hpp>
+#include <boost/geometry/util/constexpr.hpp>
 #include <boost/geometry/util/range.hpp>
 
 
@@ -102,7 +103,7 @@ struct densify_range
             strategy.apply(p0, p1, policy, len);
         }
 
-        if (BOOST_GEOMETRY_CONDITION(AppendLastPoint))
+        if BOOST_GEOMETRY_CONSTEXPR (AppendLastPoint)
         {
             convert_and_push_back(rng_out, *prev); // back(rng)
         }
@@ -130,7 +131,7 @@ struct densify_ring
 
         strategy.apply(p0, p1, policy, len);
 
-        if (BOOST_GEOMETRY_CONDITION(IsClosed2))
+        if BOOST_GEOMETRY_CONSTEXPR (IsClosed2)
         {
             convert_and_push_back(ring_out, p1);
         }

include/boost/geometry/algorithms/detail/buffer/buffer_inserter.hpp

@@ -1,7 +1,7 @@
 // Boost.Geometry (aka GGL, Generic Geometry Library)
 
 // Copyright (c) 2012-2020 Barend Gehrels, Amsterdam, the Netherlands.
-// Copyright (c) 2022 Adam Wulkiewicz, Lodz, Poland.
+// Copyright (c) 2022-2023 Adam Wulkiewicz, Lodz, Poland.
 
 // This file was modified by Oracle on 2017-2022.
 // Modifications copyright (c) 2017-2022 Oracle and/or its affiliates.
@@ -44,7 +44,7 @@
 #include <boost/geometry/strategies/buffer.hpp>
 #include <boost/geometry/strategies/side.hpp>
 
-#include <boost/geometry/util/condition.hpp>
+#include <boost/geometry/util/constexpr.hpp>
 #include <boost/geometry/util/math.hpp>
 #include <boost/geometry/util/type_traits.hpp>
 
@@ -942,17 +942,17 @@ inline void buffer_inserter(GeometryInput const& geometry_input, OutputIterator
 {
     boost::ignore_unused(visit_pieces_policy);
 
-    typedef detail::buffer::buffered_piece_collection
-    <
-        typename geometry::ring_type<GeometryOutput>::type,
-        Strategies,
-        DistanceStrategy,
-        RobustPolicy
-    > collection_type;
+    using collection_type = detail::buffer::buffered_piece_collection
+        <
+            typename geometry::ring_type<GeometryOutput>::type,
+            Strategies,
+            DistanceStrategy,
+            RobustPolicy
+        >;
     collection_type collection(strategies, distance_strategy, robust_policy);
     collection_type const& const_collection = collection;
 
-    bool const areal = util::is_areal<GeometryInput>::value;
+    static constexpr bool areal = util::is_areal<GeometryInput>::value;
 
     dispatch::buffer_inserter
         <
@@ -969,7 +969,7 @@ inline void buffer_inserter(GeometryInput const& geometry_input, OutputIterator
                  robust_policy, strategies);
 
     collection.get_turns();
-    if (BOOST_GEOMETRY_CONDITION(areal))
+    if BOOST_GEOMETRY_CONSTEXPR (areal)
     {
         collection.check_turn_in_original();
     }
@@ -989,7 +989,7 @@ inline void buffer_inserter(GeometryInput const& geometry_input, OutputIterator
     // phase 1: turns (after enrichment/clustering)
     visit_pieces_policy.apply(const_collection, 1);
 
-    if (BOOST_GEOMETRY_CONDITION(areal))
+    if BOOST_GEOMETRY_CONSTEXPR (areal)
     {
         collection.deflate_check_turns();
     }
@@ -1001,8 +1001,7 @@ inline void buffer_inserter(GeometryInput const& geometry_input, OutputIterator
     // - the output is counter clockwise
     // and avoid reversing twice
     bool reverse = distance_strategy.negative() && areal;
-    if (BOOST_GEOMETRY_CONDITION(
-            geometry::point_order<GeometryOutput>::value == counterclockwise))
+    if BOOST_GEOMETRY_CONSTEXPR (geometry::point_order<GeometryOutput>::value == counterclockwise)
     {
         reverse = ! reverse;
     }
@@ -1011,9 +1010,12 @@ inline void buffer_inserter(GeometryInput const& geometry_input, OutputIterator
         collection.reverse();
     }
 
-    if (BOOST_GEOMETRY_CONDITION(distance_strategy.negative() && areal))
+    if BOOST_GEOMETRY_CONSTEXPR (areal)
     {
-        collection.discard_nonintersecting_deflated_rings();
+        if (distance_strategy.negative())
+        {
+            collection.discard_nonintersecting_deflated_rings();
+        }
     }
 
     collection.template assign<GeometryOutput>(out);

include/boost/geometry/util/constexpr.hpp

@@ -0,0 +1,27 @@
+// Boost.Geometry
+ 
+// Copyright (c) 2023 Adam Wulkiewicz, Lodz, Poland.
+
+// 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_UTIL_CONSTEXPR_HPP
+#define BOOST_GEOMETRY_UTIL_CONSTEXPR_HPP
+
+
+#include <boost/geometry/util/condition.hpp>
+
+
+#ifndef BOOST_NO_CXX17_IF_CONSTEXPR
+
+#define BOOST_GEOMETRY_CONSTEXPR(CONDITION) constexpr (CONDITION)
+
+#else
+
+#define BOOST_GEOMETRY_CONSTEXPR(CONDITION) (BOOST_GEOMETRY_CONDITION(CONDITION))
+
+#endif
+
+
+#endif // BOOST_GEOMETRY_UTIL_CONSTEXPR_HPP