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| <a name="boost.signals2.trackable"></a><div class="titlepage"></div> |
| <div class="refnamediv"> |
| <h2><span class="refentrytitle">Class trackable</span></h2> |
| <p>boost::signals2::trackable — Provided to ease porting for code using the boost::signals::trackable class from |
| the original Boost.Signals library.</p> |
| </div> |
| <h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> |
| <div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../signals2/reference.html#header.boost.signals2.trackable_hpp" title="Header <boost/signals2/trackable.hpp>">boost/signals2/trackable.hpp</a>> |
| |
| </span> |
| <span class="keyword">class</span> <a class="link" href="trackable.html" title="Class trackable">trackable</a> <span class="special">{</span> |
| <span class="keyword">public</span><span class="special">:</span> |
| <span class="comment">// <a class="link" href="trackable.html#boost.signals2.trackableconstruct-copy-destruct">construct/copy/destruct</a></span> |
| <a class="link" href="trackable.html#id1133903-bb"><span class="identifier">trackable</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> |
| <a class="link" href="trackable.html#id644901-bb"><span class="identifier">trackable</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="trackable.html" title="Class trackable">trackable</a><span class="special">&</span><span class="special">)</span><span class="special">;</span> |
| trackable& <a class="link" href="trackable.html#id644946-bb"><span class="keyword">operator</span><span class="special">=</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="trackable.html" title="Class trackable">trackable</a><span class="special">&</span><span class="special">)</span><span class="special">;</span> |
| <a class="link" href="trackable.html#id644932-bb"><span class="special">~</span><span class="identifier">trackable</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> |
| <span class="special">}</span><span class="special">;</span></pre></div> |
| <div class="refsect1"> |
| <a name="id2564348"></a><h2>Description</h2> |
| <p>Use of the <code class="computeroutput">trackable</code> class is not recommended |
| for new code. The <code class="computeroutput">trackable</code> class is not thread-safe |
| since <code class="computeroutput">trackable</code> objects disconnect their associated |
| connections in the <code class="computeroutput">trackable</code> destructor. |
| Since the <code class="computeroutput">trackable</code> destructor is not run until |
| after the destructors of any derived classes have completed, |
| that leaves open a window where a partially destructed |
| object can still have active connections. |
| </p> |
| <p> |
| The preferred method of automatic connection management |
| with Boost.Signals2 is to manage the lifetime of |
| tracked objects with <code class="computeroutput">shared_ptr</code>s and |
| to use the <a class="link" href="slot.html#id607569-bb">signals2::slot::track</a> |
| method to track their lifetimes.</p> |
| <p>The <code class="computeroutput">trackable</code> class provides automatic |
| disconnection of signals and slots when objects bound in |
| slots (via pointer or reference) are destroyed. |
| <code class="computeroutput">trackable</code> class may only be used as a public |
| base class for some other class; when used as such, that |
| class may be bound to function objects used as part of |
| slots. The manner in which a <code class="computeroutput">trackable</code> object |
| tracks the set of signal-slot connections it is a part of is |
| unspecified.</p> |
| <p>The actual use of <code class="computeroutput">trackable</code> is contingent |
| on the presence of appropriate |
| <a class="link" href="../visit_each.html" title="Function template visit_each">visit_each</a> overloads for any |
| type that may contain pointers or references to trackable |
| objects.</p> |
| <div class="refsect2"> |
| <a name="id2564460"></a><h3> |
| <a name="boost.signals2.trackableconstruct-copy-destruct"></a><code class="computeroutput">trackable</code> |
| public |
| construct/copy/destruct</h3> |
| <div class="orderedlist"><ol class="orderedlist" type="1"> |
| <li class="listitem"> |
| <pre class="literallayout"><a name="id1133903-bb"></a><span class="identifier">trackable</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term">Effects:</span></p></td> |
| <td><p>Sets the list of connected slots to empty.</p></td> |
| </tr> |
| <tr> |
| <td><p><span class="term">Throws:</span></p></td> |
| <td><p>Will not throw.</p></td> |
| </tr> |
| </tbody> |
| </table></div> |
| </li> |
| <li class="listitem"> |
| <pre class="literallayout"><a name="id644901-bb"></a><span class="identifier">trackable</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="trackable.html" title="Class trackable">trackable</a><span class="special">&</span> other<span class="special">)</span><span class="special">;</span></pre> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term">Effects:</span></p></td> |
| <td><p>Sets the list of connected slots to empty.</p></td> |
| </tr> |
| <tr> |
| <td><p><span class="term">Throws:</span></p></td> |
| <td><p>Will not throw.</p></td> |
| </tr> |
| <tr> |
| <td><p><span class="term">Rationale:</span></p></td> |
| <td><p>Signal-slot connections can only be created via calls to an explicit connect method, and therefore cannot be created here when trackable objects are copied.</p></td> |
| </tr> |
| </tbody> |
| </table></div> |
| </li> |
| <li class="listitem"> |
| <pre class="literallayout">trackable& <a name="id644946-bb"></a><span class="keyword">operator</span><span class="special">=</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="trackable.html" title="Class trackable">trackable</a><span class="special">&</span> other<span class="special">)</span><span class="special">;</span></pre> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term">Effects:</span></p></td> |
| <td><p>Sets the list of connected slots to empty.</p></td> |
| </tr> |
| <tr> |
| <td><p><span class="term">Returns:</span></p></td> |
| <td><p><code class="computeroutput">*this</code></p></td> |
| </tr> |
| <tr> |
| <td><p><span class="term">Throws:</span></p></td> |
| <td><p>Will not throw.</p></td> |
| </tr> |
| <tr> |
| <td><p><span class="term">Rationale:</span></p></td> |
| <td><p>Signal-slot connections can only be created via calls to an explicit connect method, and therefore cannot be created here when trackable objects are copied.</p></td> |
| </tr> |
| </tbody> |
| </table></div> |
| </li> |
| <li class="listitem"> |
| <pre class="literallayout"><a name="id644932-bb"></a><span class="special">~</span><span class="identifier">trackable</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody><tr> |
| <td><p><span class="term">Effects:</span></p></td> |
| <td><p>Disconnects all signal/slot connections that |
| contain a pointer or reference to this trackable object that |
| can be found by |
| <a class="link" href="../visit_each.html" title="Function template visit_each">visit_each</a>.</p></td> |
| </tr></tbody> |
| </table></div> |
| </li> |
| </ol></div> |
| </div> |
| </div> |
| </div> |
| <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> |
| <td align="left"></td> |
| <td align="right"><div class="copyright-footer">Copyright © 2001-2004 Douglas Gregor<br>Copyright © 2007-2009 Frank Mori Hess<p>Distributed under the Boost |
| Software License, Version 1.0. (See accompanying file |
| <code class="filename">LICENSE_1_0.txt</code> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)</p> |
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