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  28 <h2><span class="refentrytitle">Macro BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS</span></h2>
  29 <p>BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS &#8212; Specify when local functions can be passed as template parameters without introducing any run-time overhead. </p>
  30 </div>
  31 <h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2>
  32 <div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="reference.html#header.boost.local_function.config_hpp" title="Header &lt;boost/local_function/config.hpp&gt;">boost/local_function/config.hpp</a>&gt;
  33
  34 </span>BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS</pre></div>
  35 <div class="refsect1">
  36 <a name="id907270"></a><h2>Description</h2>
  37 <p>If this macro is defined to <code class="computeroutput">1</code>, this library will assume that the compiler allows to pass local classes as template parameters: </p>
  38 <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">void</span> <span class="identifier">f</span><span class="special">(</span><span class="keyword">void</span><span class="special">)</span> <span class="special">{</span><span class="special">}</span>
  39
  40 <span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">void</span><span class="special">)</span> <span class="special">{</span>
  41     <span class="keyword">struct</span> <span class="identifier">local_class</span> <span class="special">{</span><span class="special">}</span><span class="special">;</span>
  42     <span class="identifier">f</span><span class="special">&lt;</span><span class="identifier">local_class</span><span class="special">&gt;</span><span class="special">(</span><span class="special">)</span><span class="special">;</span>
  43     <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
  44 <span class="special">}</span>
  45 </pre>
  46 <p> This is the case for C++11 compilers and some C++03 compilers (e.g., MSVC), but it is not the case in general for most C++03 compilers (including GCC). This will allow the library to pass local functions as template parameters without introducing any run-time overhead (specifically without preventing the compiler from optimizing local function calls by inlining their assembly code).</p>
  47 <p>If this macro is defined to <code class="computeroutput">0</code> instead, this library will introduce a run-time overhead associated to resolving a function pointer call in order to still allow to pass the local functions as template parameters.</p>
  48 <p>It is recommended to leave this macro undefined. In this case, the library will automatically define this macro to <code class="computeroutput">0</code> if the Boost.Config macro <code class="computeroutput">BOOST_NO_CXX11_LOCAL_CLASS_TEMPLATE_PARAMETERS</code> is defined for the specific compiler, and to <code class="computeroutput">1</code> otherwise.</p>
  49 <p><span class="bold"><strong>See:</strong></span> <a class="link" href="boost_localfunction/getting_started.html" title="Getting Started"> Getting Started</a> section,  <a class="link" href="boost_localfunction/advanced_topics.html" title="Advanced Topics"> Advanced Topics</a> section,  <code class="computeroutput"><a class="link" href="BOOST_LOCAL_FUNCTION_NAME.html" title="Macro BOOST_LOCAL_FUNCTION_NAME">BOOST_LOCAL_FUNCTION_NAME</a></code>. </p>
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  54 <td align="right"><div class="copyright-footer">Copyright &#169; 2009-2012 Lorenzo
  55       Caminiti<p>
  56         Distributed under the Boost Software License, Version 1.0 (see accompanying
  57         file LICENSE_1_0.txt or a 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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