default empty constructor (#5518)

Signed-off-by: Guillaume Doisy <guillaume@dexory.com>
Co-authored-by: Guillaume Doisy <guillaume@dexory.com>

Author: doisyg

nav2_behavior_tree/include/nav2_behavior_tree/bt_action_server.hpp

@@ -53,11 +53,11 @@ class BtActionServer
     const std::string & action_name,
     const std::vector<std::string> & plugin_lib_names,
     const std::string & default_bt_xml_filename,
-    const std::vector<std::string> & search_directories,
     OnGoalReceivedCallback on_goal_received_callback,
     OnLoopCallback on_loop_callback,
     OnPreemptCallback on_preempt_callback,
-    OnCompletionCallback on_completion_callback);
+    OnCompletionCallback on_completion_callback,
+    const std::vector<std::string> & search_directories = std::vector<std::string>{});
 
   /**
    * @brief A destructor for nav2_behavior_tree::BtActionServer class

nav2_behavior_tree/include/nav2_behavior_tree/bt_action_server_impl.hpp

@@ -39,11 +39,11 @@ BtActionServer<ActionT, NodeT>::BtActionServer(
   const std::string & action_name,
   const std::vector<std::string> & plugin_lib_names,
   const std::string & default_bt_xml_filename,
-  const std::vector<std::string> & search_directories,
   OnGoalReceivedCallback on_goal_received_callback,
   OnLoopCallback on_loop_callback,
   OnPreemptCallback on_preempt_callback,
-  OnCompletionCallback on_completion_callback)
+  OnCompletionCallback on_completion_callback,
+  const std::vector<std::string> & search_directories)
 : action_name_(action_name),
   default_bt_xml_filename_(default_bt_xml_filename),
   search_directories_(search_directories),

nav2_core/include/nav2_core/behavior_tree_navigator.hpp

@@ -214,13 +214,13 @@ class BehaviorTreeNavigator : public NavigatorBase
       getName(),
       plugin_lib_names,
       default_bt_xml_filename,
-      search_directories,
       std::bind(&BehaviorTreeNavigator::onGoalReceived, this, std::placeholders::_1),
       std::bind(&BehaviorTreeNavigator::onLoop, this),
       std::bind(&BehaviorTreeNavigator::onPreempt, this, std::placeholders::_1),
       std::bind(
         &BehaviorTreeNavigator::onCompletion, this,
-        std::placeholders::_1, std::placeholders::_2));
+        std::placeholders::_1, std::placeholders::_2),
+      search_directories);
 
     bool ok = true;
     if (!bt_action_server_->on_configure()) {