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that use it are valid. Merged revisions 53047-53048 via svnmerge from https://svn.boost.org/svn/boost/trunk ........ r53047 | danieljames | 2009-05-16 15:17:20 +0100 (Sat, 16 May 2009) | 1 line Fix some validation errors. ........ r53048 | danieljames | 2009-05-16 15:23:59 +0100 (Sat, 16 May 2009) | 1 line Use a local copy of the valid HTML 4.01 icon. ........ [SVN r53258]
132 lines
3.5 KiB
HTML
132 lines
3.5 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
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"http://www.w3.org/TR/html4/loose.dtd">
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<html>
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<head>
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<meta http-equiv="Content-Language" content="en-us">
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<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
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<link href="../pool.css" rel="stylesheet" type="text/css">
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<title>singleton - Singleton</title>
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</head>
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<body>
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<img src="../../../../boost.png" width="276" height="86" alt="C++ Boost">
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<h1 align="center">singleton - Singleton</h1>
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<h2>Introduction</h2>
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<p>detail/singleton.hpp provides a way to access a Singleton of a class
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type. This is <strong>not</strong> a general Singleton solution! It is
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restricted in that the class type must have a default constructor.</p>
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<h2>Synopsis</h2>
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<pre class="code">
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namespace details {
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namespace pool {
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template <typename T>
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class singleton_default
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{
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private:
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singleton_default();
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public:
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typedef T object_type;
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static object_type & instance();
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};
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} // namespace pool
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} // namespace details
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</pre>
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<h2>Semantics</h2>
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<table border align="center" summary="">
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<caption>
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<em>Symbol Table</em>
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</caption>
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<tr>
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<th>Symbol</th>
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<th>Meaning</th>
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</tr>
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<tr>
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<td class="code">T</td>
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<td>Any class with a non-throwing default constructor and non-throwing
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destructor</td>
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</tr>
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</table><br>
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<table border align="center" summary="">
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<caption>
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<em>Requirements satisfied by <span class=
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"code">singleton_default<T></span></em>
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</caption>
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<tr>
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<th>Expression</th>
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<th>Return Type</th>
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<th>Assertion/Note/Pre/Post-Condition</th>
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</tr>
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<tr>
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<td class="code">singleton_default<T>::instance()</td>
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<td class="code">T &</td>
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<td>Returns a reference to the singleton instance</td>
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</tr>
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</table>
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<h2>Guarantees</h2>
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<p>The singleton instance is guaranteed to be constructed before
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<span class="code">main()</span> begins, and destructed after <span class=
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"code">main()</span> ends. Furthermore, it is guaranteed to be constructed
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before the first call to <span class=
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"code">singleton_default<T>::instance()</span> is complete (even if
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called before <span class="code">main()</span> begins). Thus, if there are
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not multiple threads running except within <span class=
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"code">main()</span>, and if all access to the singleton is restricted by
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mutexes, then this guarantee allows a thread-safe singleton.</p>
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<h2>Details</h2>
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<p>For details on how we provide the guarantees above, see the comments in
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the header file.</p>
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<h2>Dependencies</h2>
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<p>None.</p>
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<h2>Future Directions</h2>
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<p>This header may be replaced by a Boost singleton library.</p>
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<hr>
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<p><a href="http://validator.w3.org/check?uri=referer"><img border="0" src=
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"../../../../doc/images/valid-html401.png" alt="Valid HTML 4.01 Transitional"
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height="31" width="88"></a></p>
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<p>Revised
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<!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %B, %Y" startspan -->05
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December, 2006<!--webbot bot="Timestamp" endspan i-checksum="38516" --></p>
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<p><i>Copyright © 2000, 2001 Stephen Cleary (scleary AT jerviswebb DOT
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com)</i></p>
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<p><i>Distributed under the Boost Software License, Version 1.0. (See
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accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a>
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or copy at <a href=
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"http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</a>)</i></p>
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</body>
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</html>
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