title: Cannot include Eigen and boost/regex at the same time
body: <p>I can include each library individually but as soon as I try to include them at the same time, I get a ton of errors. I'm using Boost v1_55_0 and Eigen v3.2.1.
  Any idea what the problem might be?</p>
  
  <p>My includes look like this:</p>
  
  <pre><code>#include &lt;boost/regex.hpp&gt;
  #include &lt;Eigen&gt;
  </code></pre>
  
  <p>I'm pasting the first couple of errors below, there are over 100 of them.</p>
  
  <pre><code>Error   1   error C1189: #error :  The Eigen/Array header does no longer exist in Eigen3. All that functionality has moved to Eigen/Core.   c:\local\eigen\array    8   1   Project1
  2   IntelliSense: #error directive: The Eigen/Array header does no longer exist in Eigen3. All that functionality has moved to Eigen/Core.  c:\local\Eigen\Array    8   4   Project1
  3   IntelliSense: expected a declaration    c:\local\boost_1_55_0\boost\functional\hash\extensions.hpp  160 13  Project1
  4   IntelliSense: expected a declaration    c:\local\boost_1_55_0\boost\functional\hash\extensions.hpp  162 5   Project1
  5   IntelliSense: expected a declaration    c:\local\boost_1_55_0\boost\functional\hash\extensions.hpp  377 1   Project1
  6   IntelliSense: expected a declaration    c:\local\boost_1_55_0\boost\regex\v4\basic_regex.hpp    59  7   Project1
  7   IntelliSense: expected a declaration    c:\local\boost_1_55_0\boost\regex\v4\basic_regex.hpp    100 7   Project1
  8   IntelliSense: identifier "name" is undefined    c:\local\boost_1_55_0\boost\regex\v4\basic_regex.hpp    108 24  Project1
  9   IntelliSense: explicit type is missing ('int' assumed)  c:\local\boost_1_55_0\boost\regex\v4\basic_regex.hpp    111 4   Project1
  10  IntelliSense: a type qualifier is not allowed on a nonmember function   c:\local\boost_1_55_0\boost\regex\v4\basic_regex.hpp    136 21  Project1
  11  IntelliSense: a type qualifier is not allowed on a nonmember function   c:\local\boost_1_55_0\boost\regex\v4\basic_regex.hpp    146 33  Project1
  12  IntelliSense: expected a declaration    c:\local\boost_1_55_0\boost\regex\v4\basic_regex.hpp    151 1   Project1
  13  IntelliSense: expected a declaration    c:\local\boost_1_55_0\boost\regex\v4\basic_regex.hpp    153 1   Project1
  </code></pre>