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| <title>Serialization - <code style="white-space: normal">state_saver</code></title> |
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| <h3><a href="../../../index.htm"><img height="86" width="277" alt="C++ Boost" src="../../../boost.png" border="0"></a></h3> |
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| <h1 align="center">Serialization</h1> |
| <h2 align="center"><code style="white-space: normal">state_saver</code</h2> |
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| <p> |
| Sometimes a certain value has to change only for a limited scope. |
| This class wrapper saves a copy of the current state of some object, |
| and resets the object's state at destruction time, undoing any change the object |
| may have gone through. Here is the interface: |
| |
| <pre><code> |
| template<class T> |
| // T requirements: |
| // - POD or object semantic (cannot be reference, function, ...) |
| // - copy constructor |
| // - operator = (no-throw one preferred) |
| class state_saver : private boost::noncopyable |
| { |
| private: |
| ... // implementation |
| |
| public: |
| state_saver(T & object); |
| ~state_saver(); |
| }; |
| </code></pre> |
| |
| The complete implementation can be found |
| <a target="state_saver" href="../../../boost/serialization/state_saver.hpp">here</a> |
| |
| The following illustrates how this is expected to be used. |
| |
| <pre><code> |
| #include <boost/state_saver.hpp> |
| |
| void func(A & a) |
| boost::state_saver<A> s(a); |
| ... // alter state of a by calling non-const functions |
| ... // call other functions |
| // original state of a automatically restored on exit |
| } |
| </pre></code> |
| |
| <h3>History</h3> |
| This is a generalization of Daryle Walker's |
| <a href="../../../libs/io/doc/ios_state.html">io_state_saver</a> library. |
| <p> |
| Robert Ramey made an initial version for the serialization library. |
| <p> |
| Pavel Vozenilek made several non-obvious refinements to make it more |
| secure and boost friendly |
| |
| <hr> |
| <p><i>© Copyright <a href="http://www.rrsd.com">Robert Ramey</a> 2002-2004. |
| Distributed under the Boost Software License, Version 1.0. (See |
| accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
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