.. _program_listing_file_include_rclcpp_detail_subscription_callback_type_helper.hpp:

Program Listing for File subscription_callback_type_helper.hpp
==============================================================

|exhale_lsh| :ref:`Return to documentation for file <file_include_rclcpp_detail_subscription_callback_type_helper.hpp>` (``include/rclcpp/detail/subscription_callback_type_helper.hpp``)

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

.. code-block:: cpp

   // Copyright 2021 Open Source Robotics Foundation, Inc.
   //
   // 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 RCLCPP__DETAIL__SUBSCRIPTION_CALLBACK_TYPE_HELPER_HPP_
   #define RCLCPP__DETAIL__SUBSCRIPTION_CALLBACK_TYPE_HELPER_HPP_
   
   #include <memory>
   #include <type_traits>
   
   #include "rclcpp/function_traits.hpp"
   #include "rclcpp/message_info.hpp"
   
   namespace rclcpp
   {
   namespace detail
   {
   
   
   template<typename MessageT, typename CallbackT, typename Enable = void>
   struct SubscriptionCallbackTypeHelper
   {
     using callback_type = typename rclcpp::function_traits::as_std_function<CallbackT>::type;
   };
   
   template<typename MessageT, typename CallbackT>
   struct SubscriptionCallbackTypeHelper<
     MessageT,
     CallbackT,
     typename std::enable_if_t<
       rclcpp::function_traits::same_arguments<
         CallbackT,
         std::function<void(std::shared_ptr<const MessageT>)>
       >::value
     >
   >
   {
     using callback_type = std::function<void (std::shared_ptr<const MessageT>)>;
   };
   
   template<typename MessageT, typename CallbackT>
   struct SubscriptionCallbackTypeHelper<
     MessageT,
     CallbackT,
     typename std::enable_if_t<
       rclcpp::function_traits::same_arguments<
         CallbackT,
         std::function<void(std::shared_ptr<const MessageT>, const rclcpp::MessageInfo &)>
       >::value
     >
   >
   {
     using callback_type =
       std::function<void (std::shared_ptr<const MessageT>, const rclcpp::MessageInfo &)>;
   };
   
   template<typename MessageT, typename CallbackT>
   struct SubscriptionCallbackTypeHelper<
     MessageT,
     CallbackT,
     typename std::enable_if_t<
       rclcpp::function_traits::same_arguments<
         CallbackT,
         std::function<void(const std::shared_ptr<const MessageT> &)>
       >::value
     >
   >
   {
     using callback_type = std::function<void (const std::shared_ptr<const MessageT> &)>;
   };
   
   template<typename MessageT, typename CallbackT>
   struct SubscriptionCallbackTypeHelper<
     MessageT,
     CallbackT,
     typename std::enable_if_t<
       rclcpp::function_traits::same_arguments<
         CallbackT,
         std::function<void(const std::shared_ptr<const MessageT> &, const rclcpp::MessageInfo &)>
       >::value
     >
   >
   {
     using callback_type =
       std::function<void (const std::shared_ptr<const MessageT> &, const rclcpp::MessageInfo &)>;
   };
   
   template<typename MessageT, typename CallbackT>
   struct SubscriptionCallbackTypeHelper<
     MessageT,
     CallbackT,
     typename std::enable_if_t<
       rclcpp::function_traits::same_arguments<
         CallbackT,
         std::function<void(std::shared_ptr<MessageT>)>
       >::value
     >
   >
   {
     using callback_type = std::function<void (std::shared_ptr<MessageT>)>;
   };
   
   template<typename MessageT, typename CallbackT>
   struct SubscriptionCallbackTypeHelper<
     MessageT,
     CallbackT,
     typename std::enable_if_t<
       rclcpp::function_traits::same_arguments<
         CallbackT,
         std::function<void(std::shared_ptr<MessageT>, const rclcpp::MessageInfo &)>
       >::value
     >
   >
   {
     using callback_type =
       std::function<void (std::shared_ptr<MessageT>, const rclcpp::MessageInfo &)>;
   };
   
   }  // namespace detail
   }  // namespace rclcpp
   
   #endif  // RCLCPP__DETAIL__SUBSCRIPTION_CALLBACK_TYPE_HELPER_HPP_