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  27 <a name="math_toolkit.main_overview.threads"></a><a class="link" href="threads.html" title="Thread Safety"> Thread Safety</a>
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  29 <p>
  30         The library is fully thread safe and re-entrant provided the function and
  31         class templates in the library are instantiated with built-in floating point
  32         types: i.e. the types <code class="computeroutput"><span class="keyword">float</span></code>,
  33         <code class="computeroutput"><span class="keyword">double</span></code> and <code class="computeroutput"><span class="keyword">long</span>
  34         <span class="keyword">double</span></code>.
  35       </p>
  36 <p>
  37         However, the library <span class="bold"><strong>is not thread safe</strong></span>
  38         when used with user-defined (i.e. class type) numeric types.
  39       </p>
  40 <p>
  41         The reason for the latter limitation is the need to initialise symbolic constants
  42         using constructs such as:
  43       </p>
  44 <pre class="programlisting"><span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="identifier">coefficient_array</span> <span class="special">=</span> <span class="special">{</span> <span class="special">...</span> <span class="identifier">list</span> <span class="identifier">of</span> <span class="identifier">values</span> <span class="special">...</span> <span class="special">};</span>
  45 </pre>
  46 <p>
  47         Which is always thread safe when T is a built-in floating point type, but
  48         not when T is a user defined type: as in this case there is a need for T's
  49         constructors to be run, leading to potential race conditions.
  50       </p>
  51 <p>
  52         This limitation may be addressed in a future release.
  53       </p>
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  57 <td align="right"><div class="copyright-footer">Copyright © 2006 , 2007, 2008 John Maddock, Paul A. Bristow, Hubert
  58       Holin, Xiaogang Zhang, Bruno Lalande and Johan Råde<p>
  59         Distributed under the Boost Software License, Version 1.0. (See accompanying
  60         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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