<!doctype HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <!-- (C) Copyright 2002-4 Robert Ramey - http://www.rrsd.com . Use, modification and distribution is subject to 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) --> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <link rel="stylesheet" type="text/css" href="../../../boost.css"> <link rel="stylesheet" type="text/css" href="style.css"> <title>Serialization - <code style="white-space: normal">state_saver</code></title> </head> <body link="#0000ff" vlink="#800080"> <table border="0" cellpadding="7" cellspacing="0" width="100%" summary="header"> <tr> <td valign="top" width="300"> <h3><a href="../../../index.htm"><img height="86" width="277" alt="C++ Boost" src="../../../boost.png" border="0"></a></h3> </td> <td valign="top"> <h1 align="center">Serialization</h1> <h2 align="center"><code style="white-space: normal">state_saver</code</h2> </td> </tr> </table> <hr> <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) </i></p> </body> </html>