Added a get_socket_descriptor() function to the connection class.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%402903

dlib/sockets/sockets_kernel_1.cpp

@@ -367,6 +367,15 @@ namespace dlib
         return temp;
     }
 
+// ----------------------------------------------------------------------------------------
+
+    connection::socket_descriptor_type connection::
+    get_socket_descriptor (
+    ) const
+    {
+        return connection_socket.val;
+    }
+
 // ----------------------------------------------------------------------------------------
 // ----------------------------------------------------------------------------------------
     // listener object

dlib/sockets/sockets_kernel_1.h

@@ -13,6 +13,7 @@
 #include <string>
 #include "../threads.h"
 #include "../smart_pointers.h"
+#include "../uintn.h"
 
 
 namespace dlib
@@ -129,6 +130,15 @@ namespace dlib
         int shutdown (
         );
 
+        // I would use SOCKET here but I don't want to include the windows
+        // header files since they bring in a bunch of unpleasantness.  So
+        // I'm doing this instead which should ultimately be the same type
+        // as the SOCKET win the windows API.
+        typedef unsigned_type<void*>::type socket_descriptor_type;
+
+        socket_descriptor_type get_socket_descriptor (
+        ) const;
+
     private:
    
         bool sd_called (

dlib/sockets/sockets_kernel_2.h

@@ -177,6 +177,11 @@ namespace dlib
             return temp;
         }
 
+        typedef int socket_descriptor_type;
+
+        socket_descriptor_type get_socket_descriptor (
+        ) const { return connection_socket; }
+
     private:
 
 

dlib/sockets/sockets_kernel_abstract.h

@@ -331,6 +331,20 @@ namespace dlib
                 - returns OTHER_ERROR if there was an error 
         !*/
 
+        typedef platform_specific_type socket_descriptor_type;
+        socket_descriptor_type get_socket_descriptor (
+        ) const;
+        /*!
+            ensures
+                - returns the underlying socket descriptor for this connection
+                  object.  The reason you might want access to this is to 
+                  pass it to some other library that requires a socket file 
+                  descriptor.  However, if you do this then you probably shouldn't 
+                  use the dlib::connection read() and write() anymore since
+                  whatever you are doing with the socket descriptor is probably 
+                  doing I/O with the socket.
+        !*/
+
     private:
         // restricted functions
         connection();