Get rid of boost::math::constants::* and M_PI in favor of std::numbers (#6916)

src/extractor/intersection/intersection_analysis.cpp

@@ -6,6 +6,7 @@
 #include "util/coordinate_calculation.hpp"
 
 #include <boost/optional/optional_io.hpp>
+#include <numbers>
 
 namespace osrm::extractor::intersection
 {
@@ -79,11 +80,11 @@ namespace
 {
 double findAngleBisector(double alpha, double beta)
 {
-    alpha *= M_PI / 180.;
-    beta *= M_PI / 180.;
+    alpha *= std::numbers::pi / 180.;
+    beta *= std::numbers::pi / 180.;
     const auto average =
-        180. * std::atan2(std::sin(alpha) + std::sin(beta), std::cos(alpha) + std::cos(beta)) /
-        M_PI;
+        180. * std::atan2(std::sin(alpha) + std::sin(beta), std::cos(alpha) + std::cos(beta)) *
+        std::numbers::inv_pi;
     return std::fmod(average + 360., 360.);
 }
 

src/extractor/intersection/mergable_road_detector.cpp

@@ -351,7 +351,7 @@ bool MergableRoadDetector::IsCircularShape(const NodeID intersection_node,
     //      ----         ----
     //          \       /
     //           -------
-    const auto constexpr CIRCULAR_POLYGON_ISOPERIMETRIC_LOWER_BOUND = 0.85 / (4 * M_PI);
+    const auto constexpr CIRCULAR_POLYGON_ISOPERIMETRIC_LOWER_BOUND = 0.85 / (4 * std::numbers::pi);
     if (connect_again && coordinates_to_the_left.front() == coordinates_to_the_left.back())
     { // if the left and right roads connect again and are closed polygons ...
         const auto area = util::coordinate_calculation::computeArea(coordinates_to_the_left);
@@ -359,7 +359,7 @@ bool MergableRoadDetector::IsCircularShape(const NodeID intersection_node,
         const auto area_to_squared_perimeter_ratio = std::abs(area) / (perimeter * perimeter);
 
         // then don't merge roads if A/L² is greater than the lower bound
-        BOOST_ASSERT(area_to_squared_perimeter_ratio <= 1. / (4 * M_PI));
+        BOOST_ASSERT(area_to_squared_perimeter_ratio <= 1. / (4 * std::numbers::pi));
         if (area_to_squared_perimeter_ratio >= CIRCULAR_POLYGON_ISOPERIMETRIC_LOWER_BOUND)
             return true;
     }

src/guidance/roundabout_handler.cpp

@@ -337,7 +337,7 @@ RoundaboutType RoundaboutHandler::getRoundaboutType(const NodeID nid) const
         return RoundaboutType::RoundaboutIntersection;
     }
 
-    const double radius = roundabout_length / (2 * M_PI);
+    const double radius = roundabout_length * 0.5 * std::numbers::inv_pi;
 
     // Looks like a rotary: large roundabout with dedicated name
     // do we have a dedicated name for the rotary, if not its a roundabout

src/util/coordinate_calculation.cpp

@@ -146,7 +146,6 @@ double bearing(const Coordinate coordinate_1, const Coordinate coordinate_2)
 
 double computeAngle(const Coordinate first, const Coordinate second, const Coordinate third)
 {
-    using namespace boost::math::constants;
     using namespace coordinate_calculation;
 
     if (first == second || second == third)
@@ -163,7 +162,7 @@ double computeAngle(const Coordinate first, const Coordinate second, const Coord
     const double v2y =
         web_mercator::latToY(toFloating(third.lat)) - web_mercator::latToY(toFloating(second.lat));
 
-    double angle = (atan2_lookup(v2y, v2x) - atan2_lookup(v1y, v1x)) * 180. / pi<double>();
+    double angle = (atan2_lookup(v2y, v2x) - atan2_lookup(v1y, v1x)) * 180. * std::numbers::inv_pi;
 
     while (angle < 0.)
     {