.. _program_listing_file__tmp_ws_src_fastrtps_include_fastdds_rtps_security_common_Handle.h:

Program Listing for File Handle.h
=================================

|exhale_lsh| :ref:`Return to documentation for file <file__tmp_ws_src_fastrtps_include_fastdds_rtps_security_common_Handle.h>` (``/tmp/ws/src/fastrtps/include/fastdds/rtps/security/common/Handle.h``)

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

.. code-block:: cpp

   // Copyright 2016 Proyectos y Sistemas de Mantenimiento SL (eProsima).
   //
   // 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 _FASTDDS_RTPS_SECURITY_COMMON_HANDLE_H_
   #define _FASTDDS_RTPS_SECURITY_COMMON_HANDLE_H_
   
   #include <memory>
   #include <string>
   
   namespace eprosima {
   namespace fastrtps {
   namespace rtps {
   namespace security {
   
   class Handle : public std::enable_shared_from_this<Handle>
   {
   public:
   
       const std::string& get_class_id() const
       {
           return class_id_;
       }
   
       virtual bool nil() const = 0;
   
   protected:
   
       Handle(
               const std::string& class_id)
           : class_id_(class_id)
       {
       }
   
       virtual ~Handle()
       {
       }
   
   private:
   
       std::string class_id_;
   };
   
   template<typename T, typename F>
   class HandleImpl : public Handle
   {
       friend F;
   
   protected:
   
       HandleImpl()
           : Handle(T::class_id_)
           , impl_(new T)
       {
       }
   
       virtual ~HandleImpl() = default;
   
   public:
   
       typedef T type;
   
       static HandleImpl<T, F>& narrow(
               Handle& handle)
       {
           if (handle.get_class_id().compare(T::class_id_) == 0)
           {
               return reinterpret_cast<HandleImpl<T, F>&>(handle);
           }
   
           return HandleImpl<T, F>::nil_handle;
       }
   
       static const HandleImpl<T, F>& narrow(
               const Handle& handle)
       {
           if (handle.get_class_id().compare(T::class_id_) == 0)
           {
               return reinterpret_cast<const HandleImpl<T, F>&>(handle);
           }
   
           return HandleImpl<T, F>::nil_handle;
       }
   
       bool nil() const override
       {
           return impl_ ? false : true;
       }
   
       T* operator *()
       {
           return impl_.get();
       }
   
       const T* operator *() const
       {
           return impl_.get();
       }
   
       T* operator ->()
       {
           return impl_.get();
       }
   
       const T* operator ->() const
       {
           return impl_.get();
       }
   
       static HandleImpl<T, F> nil_handle;
   
   private:
   
       explicit HandleImpl(
               bool)
           : Handle(T::class_id_)
       {
       }
   
       std::unique_ptr<T> impl_;
   };
   
   template<typename T, typename F>
   HandleImpl<T, F> HandleImpl<T, F>::nil_handle(true);
   
   class NilHandle : public Handle
   {
   public:
   
       NilHandle()
           : Handle("nil_handle")
       {
       }
   
       virtual ~NilHandle() = default;
   
       bool nil() const override
       {
           return true;
       }
   
   };
   
   
   // Define common handlers
   typedef Handle IdentityHandle;
   
   typedef Handle PermissionsHandle;
   
   typedef Handle SecretHandle;
   
   typedef Handle ParticipantCryptoHandle;
   typedef Handle EntityCryptoHandle;
   typedef Handle DatawriterCryptoHandle;
   typedef Handle DatareaderCryptoHandle;
   
   } //namespace security
   } //namespace rtps
   } //namespace fastrtps
   } //namespace eprosima
   
   #endif // _FASTDDS_RTPS_SECURITY_COMMON_HANDLE_H_