title: Can't link against Boost.Thread 1.46.1 with MinGW 4.5.2
body: <p>I've built boost using:</p>
  
  <pre><code>bjam --toolset=gcc --with-thread stage
  </code></pre>
  
  <p>Whenever I'm trying to actually use Boost.Thread I'm getting undefined references although I link against it. It doesn't happen with other Boost libraries like Regex or System.</p>
  
  <pre><code>&gt;g++ main.cpp -I. -L. -lboost_thread-mgw45-mt-1_46_1
  C:\Users\jhasse\AppData\Local\Temp\ccjYfDox.o:main.cpp:(.text+0xf): undefined reference to `_imp___ZN5boost6thread20hardware_concurrencyEv'
  collect2: ld returned 1 exit status
  </code></pre>
  
  <p>Example program:</p>
  
  <pre><code>#include &lt;boost/thread.hpp&gt;
  #include &lt;iostream&gt;
  
  int main()
  {
      std::cout &lt;&lt; boost::thread::hardware_concurrency() &lt;&lt; std::endl;
  }
  </code></pre>
  
  <p>What am I doing wrong?</p>