Explicitly delete copy construction and assignment for derived socket classes.

asio/include/asio/basic_datagram_socket.hpp

@@ -1066,6 +1066,11 @@ public:
   }
 
 private:
+  // Disallow copying and assignment.
+  basic_datagram_socket(const basic_datagram_socket&) ASIO_DELETED;
+  basic_datagram_socket& operator=(
+      const basic_datagram_socket&) ASIO_DELETED;
+
   class initiate_async_send
   { 
   public:

asio/include/asio/basic_raw_socket.hpp

@@ -1058,6 +1058,10 @@ public:
   }
 
 private:
+  // Disallow copying and assignment.
+  basic_raw_socket(const basic_raw_socket&) ASIO_DELETED;
+  basic_raw_socket& operator=(const basic_raw_socket&) ASIO_DELETED;
+
   class initiate_async_send
   {
   public:

asio/include/asio/basic_seq_packet_socket.hpp

@@ -679,6 +679,11 @@ public:
   }
 
 private:
+  // Disallow copying and assignment.
+  basic_seq_packet_socket(const basic_seq_packet_socket&) ASIO_DELETED;
+  basic_seq_packet_socket& operator=(
+      const basic_seq_packet_socket&) ASIO_DELETED;
+
   class initiate_async_send
   {
   public:

asio/include/asio/basic_stream_socket.hpp

@@ -973,6 +973,10 @@ public:
   }
 
 private:
+  // Disallow copying and assignment.
+  basic_stream_socket(const basic_stream_socket&) ASIO_DELETED;
+  basic_stream_socket& operator=(const basic_stream_socket&) ASIO_DELETED;
+
   class initiate_async_send
   {
   public: