Use std::variant instead of mapbox::util::variant (#6903)

include/engine/api/base_result.hpp

@@ -2,7 +2,7 @@
 #define ENGINE_API_BASE_RESULT_HPP
 
 #include <flatbuffers/flatbuffers.h>
-#include <mapbox/variant.hpp>
+#include <variant>
 
 #include <string>
 
@@ -10,8 +10,7 @@
 
 namespace osrm::engine::api
 {
-using ResultT =
-    mapbox::util::variant<util::json::Object, std::string, flatbuffers::FlatBufferBuilder>;
+using ResultT = std::variant<util::json::Object, std::string, flatbuffers::FlatBufferBuilder>;
 } // namespace osrm::engine::api
 
 #endif

include/engine/api/json_factory.hpp

@@ -41,7 +41,7 @@ inline bool hasValidLanes(const guidance::IntermediateIntersection &intersection
     return intersection.lanes.lanes_in_turn > 0;
 }
 
-util::json::Array coordinateToLonLat(const util::Coordinate &coordinate);
+util::json::Value coordinateToLonLat(const util::Coordinate &coordinate);
 
 /**
  * Ensures that a bearing value is a whole number, and clamped to the range 0-359
@@ -79,7 +79,7 @@ util::json::Object makeGeoJSONGeometry(ForwardIter begin, ForwardIter end)
         coordinates.values.push_back(location);
         coordinates.values.push_back(location);
     }
-    geojson.values["coordinates"] = std::move(coordinates);
+    geojson.values["coordinates"] = util::json::Value{std::move(coordinates)};
 
     return geojson;
 }

include/engine/api/match_api.hpp

@@ -30,14 +30,14 @@ class MatchAPI final : public RouteAPI
                       osrm::engine::api::ResultT &response) const
     {
         BOOST_ASSERT(sub_matchings.size() == sub_routes.size());
-        if (response.is<flatbuffers::FlatBufferBuilder>())
+        if (std::holds_alternative<flatbuffers::FlatBufferBuilder>(response))
         {
-            auto &fb_result = response.get<flatbuffers::FlatBufferBuilder>();
+            auto &fb_result = std::get<flatbuffers::FlatBufferBuilder>(response);
             MakeResponse(sub_matchings, sub_routes, fb_result);
         }
         else
         {
-            auto &json_result = response.get<util::json::Object>();
+            auto &json_result = std::get<util::json::Object>(response);
             MakeResponse(sub_matchings, sub_routes, json_result);
         }
     }

include/engine/api/nearest_api.hpp

@@ -29,14 +29,14 @@ class NearestAPI final : public BaseAPI
         BOOST_ASSERT(phantom_nodes.size() == 1);
         BOOST_ASSERT(parameters.coordinates.size() == 1);
 
-        if (response.is<flatbuffers::FlatBufferBuilder>())
+        if (std::holds_alternative<flatbuffers::FlatBufferBuilder>(response))
         {
-            auto &fb_result = response.get<flatbuffers::FlatBufferBuilder>();
+            auto &fb_result = std::get<flatbuffers::FlatBufferBuilder>(response);
             MakeResponse(phantom_nodes, fb_result);
         }
         else
         {
-            auto &json_result = response.get<util::json::Object>();
+            auto &json_result = std::get<util::json::Object>(response);
             MakeResponse(phantom_nodes, json_result);
         }
     }

include/engine/api/route_api.hpp

@@ -50,14 +50,14 @@ class RouteAPI : public BaseAPI
     {
         BOOST_ASSERT(!raw_routes.routes.empty());
 
-        if (response.is<flatbuffers::FlatBufferBuilder>())
+        if (std::holds_alternative<flatbuffers::FlatBufferBuilder>(response))
         {
-            auto &fb_result = response.get<flatbuffers::FlatBufferBuilder>();
+            auto &fb_result = std::get<flatbuffers::FlatBufferBuilder>(response);
             MakeResponse(raw_routes, waypoint_candidates, fb_result);
         }
         else
         {
-            auto &json_result = response.get<util::json::Object>();
+            auto &json_result = std::get<util::json::Object>(response);
             MakeResponse(raw_routes, waypoint_candidates, json_result);
         }
     }
@@ -158,8 +158,8 @@ class RouteAPI : public BaseAPI
     }
 
     template <typename ForwardIter>
-    mapbox::util::variant<flatbuffers::Offset<flatbuffers::String>,
-                          flatbuffers::Offset<flatbuffers::Vector<const fbresult::Position *>>>
+    std::variant<flatbuffers::Offset<flatbuffers::String>,
+                 flatbuffers::Offset<flatbuffers::Vector<const fbresult::Position *>>>
     MakeGeometry(flatbuffers::FlatBufferBuilder &builder, ForwardIter begin, ForwardIter end) const
     {
         if (parameters.geometries == RouteParameters::GeometriesType::Polyline)
@@ -408,8 +408,8 @@ class RouteAPI : public BaseAPI
 
         // Fill geometry
         auto overview = MakeOverview(leg_geometries);
-        mapbox::util::variant<flatbuffers::Offset<flatbuffers::String>,
-                              flatbuffers::Offset<flatbuffers::Vector<const fbresult::Position *>>>
+        std::variant<flatbuffers::Offset<flatbuffers::String>,
+                     flatbuffers::Offset<flatbuffers::Vector<const fbresult::Position *>>>
             geometry;
         if (overview)
         {
@@ -426,8 +426,7 @@ class RouteAPI : public BaseAPI
         routeObject.add_legs(legs_vector);
         if (overview)
         {
-            mapbox::util::apply_visitor(GeometryVisitor<fbresult::RouteObjectBuilder>(routeObject),
-                                        geometry);
+            std::visit(GeometryVisitor<fbresult::RouteObjectBuilder>(routeObject), geometry);
         }
 
         return routeObject.Finish();
@@ -644,7 +643,7 @@ class RouteAPI : public BaseAPI
         stepBuilder.add_rotary_pronunciation(rotary_pronunciation_string);
         stepBuilder.add_intersections(intersections_vector);
         stepBuilder.add_maneuver(maneuver_buffer);
-        mapbox::util::apply_visitor(GeometryVisitor<fbresult::StepBuilder>(stepBuilder), geometry);
+        std::visit(GeometryVisitor<fbresult::StepBuilder>(stepBuilder), geometry);
         return stepBuilder.Finish();
     };
 

include/engine/api/table_api.hpp

@@ -50,14 +50,14 @@ class TableAPI final : public BaseAPI
                  const std::vector<TableCellRef> &fallback_speed_cells,
                  osrm::engine::api::ResultT &response) const
     {
-        if (response.is<flatbuffers::FlatBufferBuilder>())
+        if (std::holds_alternative<flatbuffers::FlatBufferBuilder>(response))
         {
-            auto &fb_result = response.get<flatbuffers::FlatBufferBuilder>();
+            auto &fb_result = std::get<flatbuffers::FlatBufferBuilder>(response);
             MakeResponse(tables, candidates, fallback_speed_cells, fb_result);
         }
         else
         {
-            auto &json_result = response.get<util::json::Object>();
+            auto &json_result = std::get<util::json::Object>(response);
             MakeResponse(tables, candidates, fallback_speed_cells, json_result);
         }
     }
@@ -377,7 +377,8 @@ class TableAPI final : public BaseAPI
                                return util::json::Value(
                                    util::json::Number(from_alias<double>(duration) / 10.));
                            });
-            json_table.values.push_back(std::move(json_row));
+
+            json_table.values.push_back(util::json::Value{json_row});
         }
         return json_table;
     }
@@ -406,7 +407,7 @@ class TableAPI final : public BaseAPI
                                return util::json::Value(util::json::Number(
                                    std::round(from_alias<double>(distance) * 10) / 10.));
                            });
-            json_table.values.push_back(std::move(json_row));
+            json_table.values.push_back(util::json::Value{json_row});
         }
         return json_table;
     }
@@ -415,15 +416,18 @@ class TableAPI final : public BaseAPI
     MakeEstimatesTable(const std::vector<TableCellRef> &fallback_speed_cells) const
     {
         util::json::Array json_table;
-        std::for_each(fallback_speed_cells.begin(),
-                      fallback_speed_cells.end(),
-                      [&](const auto &cell)
-                      {
-                          util::json::Array row;
-                          row.values.push_back(util::json::Number(cell.row));
-                          row.values.push_back(util::json::Number(cell.column));
-                          json_table.values.push_back(std::move(row));
-                      });
+        std::for_each(
+            fallback_speed_cells.begin(),
+            fallback_speed_cells.end(),
+            [&](const auto &cell)
+            {
+                util::json::Array row;
+                util::json::Value jCellRow{util::json::Number(static_cast<double>(cell.row))};
+                util::json::Value jCellColumn{util::json::Number(static_cast<double>(cell.column))};
+                row.values.push_back(jCellRow);
+                row.values.push_back(jCellColumn);
+                json_table.values.push_back(util::json::Value{row});
+            });
         return json_table;
     }
 

include/engine/api/trip_api.hpp

@@ -27,14 +27,14 @@ class TripAPI final : public RouteAPI
     {
         BOOST_ASSERT(sub_trips.size() == sub_routes.size());
 
-        if (response.is<flatbuffers::FlatBufferBuilder>())
+        if (std::holds_alternative<flatbuffers::FlatBufferBuilder>(response))
         {
-            auto &fb_result = response.get<flatbuffers::FlatBufferBuilder>();
+            auto &fb_result = std::get<flatbuffers::FlatBufferBuilder>(response);
             MakeResponse(sub_trips, sub_routes, candidates, fb_result);
         }
         else
         {
-            auto &json_result = response.get<util::json::Object>();
+            auto &json_result = std::get<util::json::Object>(response);
             MakeResponse(sub_trips, sub_routes, candidates, json_result);
         }
     }

include/engine/plugins/plugin_base.hpp

@@ -95,7 +95,7 @@ class BasePlugin
                  const std::string &message,
                  osrm::engine::api::ResultT &result) const
     {
-        mapbox::util::apply_visitor(ErrorRenderer(code, message), result);
+        std::visit(ErrorRenderer(code, message), result);
         return Status::Error;
     }
 

include/extractor/internal_extractor_edge.hpp

@@ -7,8 +7,8 @@
 #include "util/typedefs.hpp"
 
 #include <boost/assert.hpp>
-#include <mapbox/variant.hpp>
 #include <utility>
+#include <variant>
 
 namespace osrm::extractor
 {

include/extractor/maneuver_override.hpp

@@ -11,7 +11,7 @@
 #include "util/std_hash.hpp"
 #include "util/vector_view.hpp"
 
-#include <mapbox/variant.hpp>
+#include <variant>
 
 #include <algorithm>
 

include/extractor/restriction.hpp

@@ -1,12 +1,10 @@
 #ifndef RESTRICTION_HPP
 #define RESTRICTION_HPP
 
+#include "turn_path.hpp"
 #include "util/coordinate.hpp"
 #include "util/opening_hours.hpp"
 #include "util/typedefs.hpp"
-
-#include "mapbox/variant.hpp"
-#include "turn_path.hpp"
 #include <limits>
 
 namespace osrm::extractor

include/extractor/turn_path.hpp

@@ -4,7 +4,7 @@
 #include "util/typedefs.hpp"
 
 #include <algorithm>
-#include <mapbox/variant.hpp>
+#include <variant>
 #include <vector>
 
 namespace osrm::extractor
@@ -61,50 +61,50 @@ struct InputViaWayPath
 
 struct InputTurnPath
 {
-    mapbox::util::variant<InputViaNodePath, InputViaWayPath> node_or_way;
+    std::variant<InputViaNodePath, InputViaWayPath> node_or_way;
 
     TurnPathType Type() const
     {
-        BOOST_ASSERT(node_or_way.which() < TurnPathType::NUM_TURN_PATH_TYPES);
-        return static_cast<TurnPathType>(node_or_way.which());
+        BOOST_ASSERT(node_or_way.index() < TurnPathType::NUM_TURN_PATH_TYPES);
+        return static_cast<TurnPathType>(node_or_way.index());
     }
 
     OSMWayID From() const
     {
-        return node_or_way.which() == TurnPathType::VIA_NODE_TURN_PATH
-                   ? mapbox::util::get<InputViaNodePath>(node_or_way).from
-                   : mapbox::util::get<InputViaWayPath>(node_or_way).from;
+        return node_or_way.index() == TurnPathType::VIA_NODE_TURN_PATH
+                   ? std::get<InputViaNodePath>(node_or_way).from
+                   : std::get<InputViaWayPath>(node_or_way).from;
     }
 
     OSMWayID To() const
     {
-        return node_or_way.which() == TurnPathType::VIA_NODE_TURN_PATH
-                   ? mapbox::util::get<InputViaNodePath>(node_or_way).to
-                   : mapbox::util::get<InputViaWayPath>(node_or_way).to;
+        return node_or_way.index() == TurnPathType::VIA_NODE_TURN_PATH
+                   ? std::get<InputViaNodePath>(node_or_way).to
+                   : std::get<InputViaWayPath>(node_or_way).to;
     }
 
     InputViaWayPath &AsViaWayPath()
     {
-        BOOST_ASSERT(node_or_way.which() == TurnPathType::VIA_WAY_TURN_PATH);
-        return mapbox::util::get<InputViaWayPath>(node_or_way);
+        BOOST_ASSERT(node_or_way.index() == TurnPathType::VIA_WAY_TURN_PATH);
+        return std::get<InputViaWayPath>(node_or_way);
     }
 
     const InputViaWayPath &AsViaWayPath() const
     {
-        BOOST_ASSERT(node_or_way.which() == TurnPathType::VIA_WAY_TURN_PATH);
-        return mapbox::util::get<InputViaWayPath>(node_or_way);
+        BOOST_ASSERT(node_or_way.index() == TurnPathType::VIA_WAY_TURN_PATH);
+        return std::get<InputViaWayPath>(node_or_way);
     }
 
     InputViaNodePath &AsViaNodePath()
     {
-        BOOST_ASSERT(node_or_way.which() == TurnPathType::VIA_NODE_TURN_PATH);
-        return mapbox::util::get<InputViaNodePath>(node_or_way);
+        BOOST_ASSERT(node_or_way.index() == TurnPathType::VIA_NODE_TURN_PATH);
+        return std::get<InputViaNodePath>(node_or_way);
     }
 
     const InputViaNodePath &AsViaNodePath() const
     {
-        BOOST_ASSERT(node_or_way.which() == TurnPathType::VIA_NODE_TURN_PATH);
-        return mapbox::util::get<InputViaNodePath>(node_or_way);
+        BOOST_ASSERT(node_or_way.index() == TurnPathType::VIA_NODE_TURN_PATH);
+        return std::get<InputViaNodePath>(node_or_way);
     }
 };
 
@@ -175,63 +175,63 @@ struct ViaWayPath
 // between node/way paths
 struct TurnPath
 {
-    mapbox::util::variant<ViaNodePath, ViaWayPath> node_or_way;
+    std::variant<ViaNodePath, ViaWayPath> node_or_way;
 
     NodeID To() const
     {
-        return node_or_way.which() == TurnPathType::VIA_NODE_TURN_PATH
-                   ? mapbox::util::get<ViaNodePath>(node_or_way).to
-                   : mapbox::util::get<ViaWayPath>(node_or_way).to;
+        return node_or_way.index() == TurnPathType::VIA_NODE_TURN_PATH
+                   ? std::get<ViaNodePath>(node_or_way).to
+                   : std::get<ViaWayPath>(node_or_way).to;
     }
 
     NodeID From() const
     {
-        return node_or_way.which() == TurnPathType::VIA_NODE_TURN_PATH
-                   ? mapbox::util::get<ViaNodePath>(node_or_way).from
-                   : mapbox::util::get<ViaWayPath>(node_or_way).from;
+        return node_or_way.index() == TurnPathType::VIA_NODE_TURN_PATH
+                   ? std::get<ViaNodePath>(node_or_way).from
+                   : std::get<ViaWayPath>(node_or_way).from;
     }
 
     NodeID FirstVia() const
     {
-        if (node_or_way.which() == TurnPathType::VIA_NODE_TURN_PATH)
+        if (node_or_way.index() == TurnPathType::VIA_NODE_TURN_PATH)
         {
-            return mapbox::util::get<ViaNodePath>(node_or_way).via;
+            return std::get<ViaNodePath>(node_or_way).via;
         }
         else
         {
-            BOOST_ASSERT(!mapbox::util::get<ViaWayPath>(node_or_way).via.empty());
-            return mapbox::util::get<ViaWayPath>(node_or_way).via[0];
+            BOOST_ASSERT(!std::get<ViaWayPath>(node_or_way).via.empty());
+            return std::get<ViaWayPath>(node_or_way).via[0];
         }
     }
 
     ViaWayPath &AsViaWayPath()
     {
-        BOOST_ASSERT(node_or_way.which() == TurnPathType::VIA_WAY_TURN_PATH);
-        return mapbox::util::get<ViaWayPath>(node_or_way);
+        BOOST_ASSERT(node_or_way.index() == TurnPathType::VIA_WAY_TURN_PATH);
+        return std::get<ViaWayPath>(node_or_way);
     }
 
     const ViaWayPath &AsViaWayPath() const
     {
-        BOOST_ASSERT(node_or_way.which() == TurnPathType::VIA_WAY_TURN_PATH);
-        return mapbox::util::get<ViaWayPath>(node_or_way);
+        BOOST_ASSERT(node_or_way.index() == TurnPathType::VIA_WAY_TURN_PATH);
+        return std::get<ViaWayPath>(node_or_way);
     }
 
     ViaNodePath &AsViaNodePath()
     {
-        BOOST_ASSERT(node_or_way.which() == TurnPathType::VIA_NODE_TURN_PATH);
-        return mapbox::util::get<ViaNodePath>(node_or_way);
+        BOOST_ASSERT(node_or_way.index() == TurnPathType::VIA_NODE_TURN_PATH);
+        return std::get<ViaNodePath>(node_or_way);
     }
 
     const ViaNodePath &AsViaNodePath() const
     {
-        BOOST_ASSERT(node_or_way.which() == TurnPathType::VIA_NODE_TURN_PATH);
-        return mapbox::util::get<ViaNodePath>(node_or_way);
+        BOOST_ASSERT(node_or_way.index() == TurnPathType::VIA_NODE_TURN_PATH);
+        return std::get<ViaNodePath>(node_or_way);
     }
 
     TurnPathType Type() const
     {
-        BOOST_ASSERT(node_or_way.which() < TurnPathType::NUM_TURN_PATH_TYPES);
-        return static_cast<TurnPathType>(node_or_way.which());
+        BOOST_ASSERT(node_or_way.index() < TurnPathType::NUM_TURN_PATH_TYPES);
+        return static_cast<TurnPathType>(node_or_way.index());
     }
 
     bool operator==(const TurnPath &other) const

include/nodejs/json_v8_renderer.hpp

@@ -29,7 +29,7 @@ struct V8Renderer
         for (const auto &keyValue : object.values)
         {
             Napi::Value child;
-            mapbox::util::apply_visitor(V8Renderer(env, child), keyValue.second);
+            std::visit(V8Renderer(env, child), keyValue.second);
             obj.Set(keyValue.first, child);
         }
         out = obj;
@@ -41,7 +41,7 @@ struct V8Renderer
         for (auto i = 0u; i < array.values.size(); ++i)
         {
             Napi::Value child;
-            mapbox::util::apply_visitor(V8Renderer(env, child), array.values[i]);
+            std::visit(V8Renderer(env, child), array.values[i]);
             a.Set(i, child);
         }
         out = a;

include/nodejs/node_osrm_support.hpp

@@ -28,6 +28,7 @@
 #include <sstream>
 #include <stdexcept>
 #include <string>
+#include <variant>
 #include <vector>
 
 #include <exception>
@@ -50,7 +51,7 @@ struct PluginParameters
     bool renderToBuffer = false;
 };
 
-using ObjectOrString = typename mapbox::util::variant<osrm::json::Object, std::string>;
+using ObjectOrString = typename std::variant<osrm::json::Object, std::string>;
 
 template <typename ResultT> inline Napi::Value render(const Napi::Env &env, const ResultT &result);
 
@@ -61,18 +62,18 @@ template <> Napi::Value inline render(const Napi::Env &env, const std::string &r
 
 template <> Napi::Value inline render(const Napi::Env &env, const ObjectOrString &result)
 {
-    if (result.is<osrm::json::Object>())
+    if (std::holds_alternative<osrm::json::Object>(result))
     {
         // Convert osrm::json object tree into matching v8 object tree
         Napi::Value value;
-        renderToV8(env, value, result.get<osrm::json::Object>());
+        renderToV8(env, value, std::get<osrm::json::Object>(result));
         return value;
     }
     else
     {
         // Return the string object as a node Buffer
         return Napi::Buffer<char>::Copy(
-            env, result.get<std::string>().data(), result.get<std::string>().size());
+            env, std::get<std::string>(result).data(), std::get<std::string>(result).size());
     }
 }
 
@@ -95,7 +96,7 @@ inline void ParseResult(const osrm::Status &result_status, osrm::json::Object &r
 
     if (result_status == osrm::Status::Error)
     {
-        throw std::logic_error(code_iter->second.get<osrm::json::String>().value.c_str());
+        throw std::logic_error(std::get<osrm::json::String>(code_iter->second).value.c_str());
     }
 
     result.values.erase(code_iter);

include/server/service/base_service.hpp

@@ -5,7 +5,7 @@
 #include "osrm/osrm.hpp"
 #include "util/coordinate.hpp"
 
-#include <mapbox/variant.hpp>
+#include <variant>
 
 #include <string>
 #include <vector>

include/util/geojson_debug_logger.hpp

@@ -51,7 +51,7 @@ class GeojsonLogger
             if (!first)
                 ofs << ",\n\t\t";
 
-            util::json::render(ofs, object.get<util::json::Object>());
+            util::json::render(ofs, std::get<util::json::Object>(object));
 
             first = false;
         }

include/util/geojson_debug_policies.hpp

@@ -51,4 +51,4 @@ struct CoordinateVectorToMultiPoint
 
 } // namespace osrm::util
 
-#endif /* OSRM_GEOJSON_DEBUG_POLICIES */
+#endif /* OSRM_GEOJSON_DEBUG_POLICIES */

include/util/geojson_debug_policy_toolkit.hpp

@@ -55,12 +55,12 @@ inline util::json::Object makeStyle(const GeojsonStyleSize size_type,
 
 struct CoordinateToJsonArray
 {
-    util::json::Array operator()(const util::Coordinate coordinate)
+    util::json::Value operator()(const util::Coordinate coordinate)
     {
         util::json::Array json_coordinate;
         json_coordinate.values.push_back(static_cast<double>(toFloating(coordinate.lon)));
         json_coordinate.values.push_back(static_cast<double>(toFloating(coordinate.lat)));
-        return json_coordinate;
+        return util::json::Value{json_coordinate};
     }
 };
 
@@ -73,7 +73,7 @@ struct NodeIdToCoordinate
 
     const std::vector<util::Coordinate> &node_coordinates;
 
-    util::json::Array operator()(const NodeID nid)
+    util::json::Value operator()(const NodeID nid)
     {
         auto coordinate = node_coordinates[nid];
         CoordinateToJsonArray converter;
@@ -108,4 +108,4 @@ inline util::json::Array makeJsonArray(const std::vector<util::Coordinate> &inpu
 }
 } // namespace osrm::util
 
-#endif /* OSRM_GEOJSON_DEBUG_POLICY_TOOLKIT_HPP */
+#endif /* OSRM_GEOJSON_DEBUG_POLICY_TOOLKIT_HPP */

include/util/json_container.hpp

@@ -31,11 +31,10 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #ifndef JSON_CONTAINER_HPP
 #define JSON_CONTAINER_HPP
 
-#include <mapbox/variant.hpp>
-
 #include <string>
 #include <unordered_map>
 #include <utility>
+#include <variant>
 #include <vector>
 
 namespace osrm::util::json
@@ -96,13 +95,7 @@ struct Null
  *
  * Dispatch on its type by either by using apply_visitor or its get function.
  */
-using Value = mapbox::util::variant<String,
-                                    Number,
-                                    mapbox::util::recursive_wrapper<Object>,
-                                    mapbox::util::recursive_wrapper<Array>,
-                                    True,
-                                    False,
-                                    Null>;
+using Value = std::variant<String, Number, Object, Array, True, False, Null>;
 
 /**
  * Typed Object.

include/util/json_deep_compare.hpp

@@ -81,10 +81,10 @@ struct Comparator
 
             const auto &rhs_child = rhs.values.find(key)->second;
             const auto &lhs_child = lhs.values.find(key)->second;
-            auto is_same = mapbox::util::apply_visitor(
-                Comparator(reason, lhs_path + "." + key, rhs_path + "." + key),
-                lhs_child,
-                rhs_child);
+            auto is_same =
+                std::visit(Comparator(reason, lhs_path + "." + key, rhs_path + "." + key),
+                           lhs_child,
+                           rhs_child);
             if (!is_same)
             {
                 return false;
@@ -104,12 +104,11 @@ struct Comparator
 
         for (auto i = 0UL; i < lhs.values.size(); ++i)
         {
-            auto is_same =
-                mapbox::util::apply_visitor(Comparator(reason,
-                                                       lhs_path + "[" + std::to_string(i) + "]",
-                                                       rhs_path + "[" + std::to_string(i) + "]"),
-                                            lhs.values[i],
-                                            rhs.values[i]);
+            auto is_same = std::visit(Comparator(reason,
+                                                 lhs_path + "[" + std::to_string(i) + "]",
+                                                 rhs_path + "[" + std::to_string(i) + "]"),
+                                      lhs.values[i],
+                                      rhs.values[i]);
             if (!is_same)
             {
                 return false;
@@ -151,8 +150,7 @@ struct Comparator
 
 inline bool compare(const Value &reference, const Value &result, std::string &reason)
 {
-    return mapbox::util::apply_visitor(
-        Comparator(reason, "reference", "result"), reference, result);
+    return std::visit(Comparator(reason, "reference", "result"), reference, result);
 }
 } // namespace osrm::util::json
 

include/util/json_renderer.hpp

@@ -67,7 +67,7 @@ template <typename Out> struct Renderer
             write('\"');
             write(it->first);
             write<>("\":");
-            mapbox::util::apply_visitor(Renderer(out), it->second);
+            std::visit(Renderer(out), it->second);
             if (++it != end)
             {
                 write(',');
@@ -81,7 +81,7 @@ template <typename Out> struct Renderer
         write('[');
         for (auto it = array.values.cbegin(), end = array.values.cend(); it != end;)
         {
-            mapbox::util::apply_visitor(Renderer(out), *it);
+            std::visit(Renderer(out), *it);
             if (++it != end)
             {
                 write(',');