address. <em>The underlying socket address stored at that pointer might be
modified</em>.
+ This template class is inherited into addressing policy classes via private
+ inheritance. Then the members supported by the respective addressing policy are made
+ available via \c using declarations (See INet4AddressingPolicy for an Example).
+
\idea We could explicitly provide open_sockaddr_p() and close_sockaddr_p()
members. sockaddr_p could always return a const * whereas open_sockaddr_p should return a
non-const pointer. The close operation would then explicitly signal, that the new value