.. _program_listing_file__tmp_ws_src_v4l2_camera_include_v4l2_camera_visibility_control.h:

Program Listing for File visibility_control.h
=============================================

|exhale_lsh| :ref:`Return to documentation for file <file__tmp_ws_src_v4l2_camera_include_v4l2_camera_visibility_control.h>` (``/tmp/ws/src/v4l2_camera/include/v4l2_camera/visibility_control.h``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   // Copyright 2019 Bold Hearts
   //
   // Licensed under the Apache License, Version 2.0 (the "License");
   // you may not use this file except in compliance with the License.
   // You may obtain a copy of the License at
   //
   //     http://www.apache.org/licenses/LICENSE-2.0
   //
   // Unless required by applicable law or agreed to in writing, software
   // distributed under the License is distributed on an "AS IS" BASIS,
   // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   // See the License for the specific language governing permissions and
   // limitations under the License.
   
   #ifndef V4L2_CAMERA__VISIBILITY_CONTROL_H_
   #define V4L2_CAMERA__VISIBILITY_CONTROL_H_
   
   // This logic was borrowed (then namespaced) from the examples on the gcc wiki:
   //     https://gcc.gnu.org/wiki/Visibility
   
   #if defined _WIN32 || defined __CYGWIN__
     #ifdef __GNUC__
       #define ROS2_V4L2_CAMERA_EXPORT __attribute__ ((dllexport))
       #define ROS2_V4L2_CAMERA_IMPORT __attribute__ ((dllimport))
     #else
       #define ROS2_V4L2_CAMERA_EXPORT __declspec(dllexport)
       #define ROS2_V4L2_CAMERA_IMPORT __declspec(dllimport)
     #endif
     #ifdef ROS2_V4L2_CAMERA_BUILDING_LIBRARY
       #define ROS2_V4L2_CAMERA_PUBLIC ROS2_V4L2_CAMERA_EXPORT
     #else
       #define ROS2_V4L2_CAMERA_PUBLIC ROS2_V4L2_CAMERA_IMPORT
     #endif
     #define ROS2_V4L2_CAMERA_PUBLIC_TYPE ROS2_V4L2_CAMERA_PUBLIC
     #define ROS2_V4L2_CAMERA_LOCAL
   #else
     #define ROS2_V4L2_CAMERA_EXPORT __attribute__ ((visibility("default")))
     #define ROS2_V4L2_CAMERA_IMPORT
     #if __GNUC__ >= 4
       #define ROS2_V4L2_CAMERA_PUBLIC __attribute__ ((visibility("default")))
       #define ROS2_V4L2_CAMERA_LOCAL  __attribute__ ((visibility("hidden")))
     #else
       #define ROS2_V4L2_CAMERA_PUBLIC
       #define ROS2_V4L2_CAMERA_LOCAL
     #endif
     #define ROS2_V4L2_CAMERA_PUBLIC_TYPE
   #endif
   
   #endif  // V4L2_CAMERA__VISIBILITY_CONTROL_H_