.. ot-topic:: cxx_design_patterns.proxy
   :dependencies: cxx03.inheritance_oo.interface,
		  cxx_design_patterns.uml,
		  cxx_design_patterns.sensor_hierarchy

.. include:: <mmlalias.txt>


Proxy
=====

.. contents::
   :local:

Problem
-------

Say an object lives outside of a client's address space, and a network
protocol must be used to access it from the client's address
space. The object has a base type, and it's that base type that should
also be used locally.

The *Proxy* pattern can also be used purely local, for example to hook
into the call to the target object.

Solution: *Proxy*
-----------------

Local Variant
.............

.. image:: /trainings/material/soup/cxx-exercises/design-patterns/proxy-local.png
   :scale: 40%

Remote Variant
..............

.. image:: /trainings/material/soup/cxx-exercises/design-patterns/proxy-remote.png

Exercises
---------

* :doc:`/trainings/material/soup/cxx-exercises/design-patterns/proxy-remote`
* :doc:`/trainings/material/soup/cxx-exercises/design-patterns/proxy-round`