Boost_1_39_0/libs/serialization/doc/state_saver.html

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  13 <title>Serialization - <code style="white-space: normal">state_saver</code></title>
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  19       <h3><a href="../../../index.htm"><img height="86" width="277" alt="C++ Boost" src="../../../boost.png" border="0"></a></h3>
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  22       <h1 align="center">Serialization</h1>
  23       <h2 align="center"><code style="white-space: normal">state_saver</code</h2>
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  28 <p>
  29 Sometimes a certain value has to change only for a limited scope.
  30 This class wrapper saves a copy of the current state of some object,
  31 and resets the object's state at destruction time, undoing any change the object
  32 may have gone through.  Here is the interface:
  33
  34 <pre><code>
  35 template<class T>
  36 // T requirements:
  37 //  - POD or object semantic (cannot be reference, function, ...)
  38 //  - copy constructor
  39 //  - operator = (no-throw one preferred)
  40 class state_saver : private boost::noncopyable
  41 {
  42 private:
  43     ... // implementation
  44
  45 public:
  46     state_saver(T & object);
  47     ~state_saver();
  48 };
  49 </code></pre>
  50
  51 The complete implementation can be found
  52 <a target="state_saver" href="../../../boost/state_saver.hpp">here</a>
  53
  54 The following illustrates how this is expected to be used.
  55
  56 <pre><code>
  57 #include &lt;boost/state_saver.hpp&gt;
  58
  59 void func(A & a)
  60     boost::state_saver&lt;A&gt; s(a);
  61     ... // alter state of a by calling non-const functions
  62     ... // call other functions
  63     // original state of a automatically restored on exit
  64 }
  65 </pre></code>
  66
  67 <h3>History</h3>
  68 This is a generalization of Daryle Walker's
  69 <a href="../../../libs/io/doc/ios_state.html">io_state_saver</a> library.
  70 <p>
  71 Robert Ramey made an initial version for the serialization library.
  72 <p>
  73 Pavel Vozenilek made several non-obvious refinements to make it more
  74 secure and boost friendly
  75
  76 <hr>
  77 <p><i>&copy; Copyright <a href="http://www.rrsd.com">Robert Ramey</a> 2002-2004.
  78 Distributed under the Boost Software License, Version 1.0. (See
  79 accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  80 </i></p>
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