title: Unresolved external symbol boost::chrono::system_clock::now(void)
body: <p>google has been unkind...</p>
  
  <p>I recently pulled down boost 1.50, and am trying to build my project using it. It's a large project, using several boost features (threads, signals, pointer classes, spirit, etc.). Some specifics:
  <br>- MSVC 9.0 (2008)
  <br>- Static linking boost</p>
  
  <p>I'm getting an error linking every resulting exe, but with chrono, which I'm not directly linking. The error is:</p>
  
  <pre><code>libboost_thread-vc90-mt-sgd-1_50.lib(thread.obj) : error LNK2019: unresolved external symbol "public: static class boost::chrono::time_point&lt;class boost::chrono::system_clock,class boost::chrono::duration&lt;__int64,class boost::ratio&lt;1,10000000&gt; &gt; &gt; __cdecl boost::chrono::system_clock::now(void)" (?now@system_clock@chrono@boost@@SA?AV?$time_point@Vsystem_clock@chrono@boost@@V?$duration@_JV?$ratio@$00$0JIJGIA@@boost@@@23@@23@XZ) referenced in function "public: bool __thiscall boost::thread::try_join_until(class boost::chrono::time_point&lt;class boost::chrono::system_clock,class boost::chrono::duration&lt;__int64,class boost::ratio&lt;1,1000000000&gt; &gt; &gt; const &amp;)" (?try_join_until@thread@boost@@QAE_NABV?$time_point@Vsystem_clock@chrono@boost@@V?$duration@_JV?$ratio@$00$0DLJKMKAA@@boost@@@23@@chrono@2@@Z)
  </code></pre>
  
  <p>I saw <a href="https://stackoverflow.com/questions/11575660/undefined-reference-to-boostchronosystem-clocknow-boost-and-cpp-net">this question</a>, but I'm not directly controlling the order of linking (rather using the auto-link capabilities). If there's a specific lib I'm missing, I can manually link it; sub-optimal, but possible. However, I have no idea what's missing. It appears (to my semi-educated view) that the symbol is externed in the chrono lib, and not in the system lib.</p>
  
  <p>Any help?</p>