Add ActorVariant class

LibCarla/source/carla/client/ActorList.cpp

@@ -7,7 +7,6 @@
 #include "carla/client/ActorList.h"
 
 #include "carla/StringUtil.h"
-#include "carla/client/Actor.h"
 #include "carla/client/detail/ActorFactory.h"
 
 #include <iterator>
@@ -15,15 +14,6 @@
 namespace carla {
 namespace client {
 
-  struct GetTypeIdVisitor {
-    const std::string &operator()(const rpc::Actor &actor) const {
-      return actor.description.id;
-    }
-    const std::string &operator()(const SharedPtr<Actor> &actor) const {
-      return actor->GetTypeId();
-    }
-  };
-
   ActorList::ActorList(
       detail::EpisodeProxy episode,
       std::vector<rpc::Actor> actors)
@@ -32,25 +22,13 @@ namespace client {
 
   ActorList ActorList::Filter(const std::string &wildcard_pattern) const {
     ActorList filtered{_episode, {}};
-    for (auto &&item : _actors) {
-      const auto &id = boost::apply_visitor(GetTypeIdVisitor(), item);
-      if (StringUtil::Match(id, wildcard_pattern)) {
-        filtered._actors.push_back(item);
+    for (auto &&actor : _actors) {
+      if (StringUtil::Match(actor.GetTypeId(), wildcard_pattern)) {
+        filtered._actors.push_back(actor);
       }
     }
     return filtered;
   }
 
-  SharedPtr<Actor> ActorList::RetrieveActor(value_type &value) const {
-    if (value.which() == 0u) {
-      value = detail::ActorFactory::MakeActor(
-          _episode,
-          boost::get<rpc::Actor>(std::move(value)),
-          GarbageCollectionPolicy::Disabled);
-    }
-    DEBUG_ASSERT(value.which() == 1u);
-    return boost::get<SharedPtr<Actor>>(value);
-  }
-
 } // namespace client
 } // namespace carla

LibCarla/source/carla/client/ActorList.h

@@ -6,27 +6,22 @@
 
 #pragma once
 
-#include "carla/Memory.h"
-#include "carla/client/detail/EpisodeProxy.h"
-#include "carla/rpc/Actor.h"
+#include "carla/client/detail/ActorVariant.h"
 
 #include <boost/iterator/transform_iterator.hpp>
-#include <boost/variant.hpp>
 
 #include <vector>
 
 namespace carla {
 namespace client {
 
-  class Actor;
-
-  class ActorList {
+  class ActorList : public EnableSharedFromThis<ActorList> {
   private:
 
     template <typename It>
     auto MakeIterator(It it) const {
       return boost::make_transform_iterator(it, [this](auto &v) {
-        return RetrieveActor(v);
+        return v.Get(_episode);
       });
     }
 
@@ -36,11 +31,11 @@ namespace client {
     ActorList Filter(const std::string &wildcard_pattern) const;
 
     SharedPtr<Actor> operator[](size_t pos) const {
-      return RetrieveActor(_actors[pos]);
+      return _actors[pos].Get(_episode);
     }
 
     SharedPtr<Actor> at(size_t pos) const {
-      return RetrieveActor(_actors.at(pos));
+      return _actors.at(pos).Get(_episode);
     }
 
     auto begin() const {
@@ -65,13 +60,9 @@ namespace client {
 
     ActorList(detail::EpisodeProxy episode, std::vector<rpc::Actor> actors);
 
-    using value_type = boost::variant<rpc::Actor, SharedPtr<Actor>>;
-
-    SharedPtr<Actor> RetrieveActor(value_type &value) const;
-
     detail::EpisodeProxy _episode;
 
-    mutable std::vector<value_type> _actors;
+    std::vector<detail::ActorVariant> _actors;
   };
 
 } // namespace client

LibCarla/source/carla/client/World.cpp

@@ -9,6 +9,7 @@
 #include "carla/Logging.h"
 #include "carla/client/Actor.h"
 #include "carla/client/ActorBlueprint.h"
+#include "carla/client/ActorList.h"
 #include "carla/client/detail/Simulator.h"
 
 #include <exception>
@@ -40,8 +41,10 @@ namespace client {
     _episode.Lock()->SetWeatherParameters(weather);
   }
 
-  ActorList World::GetActors() const {
-    return {_episode, _episode.Lock()->GetAllTheActorsInTheEpisode()};
+  SharedPtr<ActorList> World::GetActors() const {
+    return SharedPtr<ActorList>{new ActorList{
+        _episode,
+        _episode.Lock()->GetAllTheActorsInTheEpisode()}};
   }
 
   SharedPtr<Actor> World::SpawnActor(

LibCarla/source/carla/client/World.h

@@ -7,7 +7,6 @@
 #pragma once
 
 #include "carla/Memory.h"
-#include "carla/client/ActorList.h"
 #include "carla/client/detail/EpisodeProxy.h"
 #include "carla/geom/Transform.h"
 #include "carla/rpc/WeatherParameters.h"
@@ -17,6 +16,7 @@ namespace client {
 
   class Actor;
   class ActorBlueprint;
+  class ActorList;
   class BlueprintLibrary;
 
   class World {
@@ -42,7 +42,7 @@ namespace client {
 
     void SetWeather(const rpc::WeatherParameters &weather);
 
-    ActorList GetActors() const;
+    SharedPtr<ActorList> GetActors() const;
 
     SharedPtr<Actor> SpawnActor(
         const ActorBlueprint &blueprint,

LibCarla/source/carla/client/detail/ActorVariant.cpp

@@ -0,0 +1,24 @@
+// Copyright (c) 2017 Computer Vision Center (CVC) at the Universitat Autonoma
+// de Barcelona (UAB).
+//
+// This work is licensed under the terms of the MIT license.
+// For a copy, see <https://opensource.org/licenses/MIT>.
+
+#include "carla/client/detail/ActorVariant.h"
+
+#include "carla/client/detail/ActorFactory.h"
+
+namespace carla {
+namespace client {
+namespace detail {
+
+  void ActorVariant::MakeActor(EpisodeProxy episode) const {
+    _value = detail::ActorFactory::MakeActor(
+        episode,
+        boost::get<rpc::Actor>(std::move(_value)),
+        GarbageCollectionPolicy::Disabled);
+  }
+
+} // namespace detail
+} // namespace client
+} // namespace carla

LibCarla/source/carla/client/detail/ActorVariant.h

@@ -0,0 +1,87 @@
+// Copyright (c) 2017 Computer Vision Center (CVC) at the Universitat Autonoma
+// de Barcelona (UAB).
+//
+// This work is licensed under the terms of the MIT license.
+// For a copy, see <https://opensource.org/licenses/MIT>.
+
+#pragma once
+
+#include "carla/Debug.h"
+#include "carla/Memory.h"
+#include "carla/client/Actor.h"
+#include "carla/client/detail/EpisodeProxy.h"
+#include "carla/rpc/Actor.h"
+
+#include <boost/variant.hpp>
+
+namespace carla {
+namespace client {
+namespace detail {
+
+  /// Holds an Actor, but only instantiates it when needed.
+  class ActorVariant {
+  public:
+
+    ActorVariant(rpc::Actor actor)
+      : _value(actor) {}
+
+    ActorVariant(SharedPtr<client::Actor> actor)
+      : _value(actor) {}
+
+    ActorVariant &operator=(rpc::Actor actor) {
+      _value = actor;
+      return *this;
+    }
+
+    ActorVariant &operator=(SharedPtr<client::Actor> actor) {
+      _value = actor;
+      return *this;
+    }
+
+    SharedPtr<client::Actor> Get(EpisodeProxy episode) const {
+      if (_value.which() == 0u) {
+        MakeActor(episode);
+      }
+      DEBUG_ASSERT(_value.which() == 1u);
+      return boost::get<SharedPtr<client::Actor>>(_value);
+    }
+
+    const rpc::Actor &Serialize() const {
+      return boost::apply_visitor(Visitor(), _value);
+    }
+
+    actor_id_type GetId() const {
+      return Serialize().id;
+    }
+
+    const std::string &GetTypeId() const {
+      return Serialize().description.id;
+    }
+
+    bool operator==(ActorVariant rhs) const {
+      return GetId() == rhs.GetId();
+    }
+
+    bool operator!=(ActorVariant rhs) const {
+      return !(*this == rhs);
+    }
+
+  private:
+
+    struct Visitor {
+      const rpc::Actor &operator()(const rpc::Actor &actor) const {
+        return actor;
+      }
+      const rpc::Actor &operator()(const SharedPtr<client::Actor> &actor) const {
+        return actor->Serialize();
+      }
+    };
+
+    void MakeActor(EpisodeProxy episode) const;
+
+    mutable boost::variant<rpc::Actor, SharedPtr<client::Actor>> _value;
+  };
+
+} // namespace detail
+} // namespace client
+} // namespace carla

PythonAPI/source/libcarla/World.cpp

@@ -11,7 +11,6 @@
 
 #include <boost/python/suite/indexing/vector_indexing_suite.hpp>
 
-
 namespace carla {
 namespace client {
 
@@ -32,7 +31,7 @@ void export_world() {
   namespace cc = carla::client;
   namespace cg = carla::geom;
 
-  class_<cc::ActorList>("ActorList", no_init)
+  class_<cc::ActorList, boost::shared_ptr<cc::ActorList>>("ActorList", no_init)
     .def("filter", &cc::ActorList::Filter)
     .def("__getitem__", &cc::ActorList::at)
     .def("__len__", &cc::ActorList::size)