Add back the ostream operator for socket_error since it is needed by the

log_error error handler.

asio/include/asio/socket_error.hpp

@@ -21,6 +21,7 @@
 #include <cerrno>
 #include <exception>
 #include <string>
+#include <iostream>
 #include "asio/detail/pop_options.hpp"
 
 #include "asio/detail/socket_types.hpp"
@@ -242,6 +243,13 @@ public:
     return e1.code_ != e2.code_;
   }
 
+  /// Write an error message to an output stream.
+  friend std::ostream& operator<<(std::ostream& os, const socket_error& e)
+  {
+    os << e.what() << ": " << e.message();
+    return os;
+  }
+
 private:
   // The code associated with the error.
   int code_;

asio/src/examples/tutorial/daytime1/client.cpp

@@ -24,7 +24,7 @@ int main(int argc, char* argv[])
   }
   catch (asio::socket_error& e)
   {
-    std::cerr << e.what() << ": " << e.message() << std::endl;
+    std::cerr << e << std::endl;
   }
 
   return 0;

asio/src/examples/tutorial/daytime2/server.cpp

@@ -25,7 +25,7 @@ int main()
   }
   catch (asio::socket_error& e)
   {
-    std::cerr << e.what() << ": " << e.message() << std::endl;
+    std::cerr << e << std::endl;
   }
 
   return 0;

asio/src/examples/tutorial/daytime3/server.cpp

@@ -54,7 +54,7 @@ int main()
   }
   catch (asio::socket_error& e)
   {
-    std::cerr << e.what() << ": " << e.message() << std::endl;
+    std::cerr << e << std::endl;
   }
 
   return 0;

asio/src/examples/tutorial/daytime4/client.cpp

@@ -25,7 +25,7 @@ int main(int argc, char* argv[])
   }
   catch (asio::socket_error& e)
   {
-    std::cerr << e.what() << ": " << e.message() << std::endl;
+    std::cerr << e << std::endl;
   }
 
   return 0;

asio/src/examples/tutorial/daytime5/server.cpp

@@ -29,7 +29,7 @@ int main()
   }
   catch (asio::socket_error& e)
   {
-    std::cerr << e.what() << ": " << e.message() << std::endl;
+    std::cerr << e << std::endl;
   }
 
   return 0;

asio/src/examples/tutorial/daytime6/server.cpp

@@ -51,7 +51,7 @@ int main()
   }
   catch (asio::socket_error& e)
   {
-    std::cerr << e.what() << ": " << e.message() << std::endl;
+    std::cerr << e << std::endl;
   }
 
   return 0;

asio/src/examples/tutorial/daytime7/server.cpp

@@ -88,7 +88,7 @@ int main()
   }
   catch (asio::socket_error& e)
   {
-    std::cerr << e.what() << ": " << e.message() << std::endl;
+    std::cerr << e << std::endl;
   }
 
   return 0;