title: E0145 member "boost::filesystem::path::separator" may not be initialized & LINK2019 error in VS2017 using vcpkg
body: <p>I start using vcpkg in my msvc C++ project recently.</p>
  
  <p>I built the boost 1.67 and referred it in my vs project. After I installed vcpkg, I added some lib and vcpkg seems installed another boost for me and link it to my project. Unfortunately, that boost does't work. I am now having tens of error in building project. Most of them are E0145 and LINK2019. I'm new in c++ programming. I want to know how I can use the boost I built instead of the one vcpkg installed for me.</p>
  
  <p>eg. one of the error is because it changes my BOOST_NO_CXX11_CONSTEXPR and try to use constexpr while it's not supported on my pc. The error is:</p>
  
  <pre><code>E0145 member "boost::filesystem::path::separator" may not be initialized    c:\Users\admin\Libraries\boost_1_67_0\boost_1_67_0\boost\filesystem\path.hpp    65  
  </code></pre>
  
  <p>this is my own boost file but all refer is to c:\Users\xxx\vcpkg\vcpkg\installed\x86-windows\include\boost\config\detail\suffix.hpp</p>
  
  <p>instead of</p>
  
  <p>C:\Users\xxx\Libraries\boost_1_67_0\boost_1_67_0\include\boost-1_67\boost\config\detail\suffix.hpp</p>
  
  <p>What can I do to correct this? 
  The file structure of vcpkg-boost is differ from the boost 1.67 I used before. If I replace the files with 1.67 ones, I'm afraid it will be reset when I upgrade the vcpkg and its libraries. Please give me some advice on this.</p>
  
  <p>And I also got error like,</p>
  
  <pre><code>LNK2019 unresolved external symbol "__declspec(dllimport) void __cdecl boost::filesystem::path_traits::convert(char const *,char const *,class std::basic_string&lt;wchar_t,struct std::char_traits&lt;wchar_t&gt;,class std::allocator&lt;wchar_t&gt; &gt; &amp;,class std::codecvt&lt;wchar_t,char,struct _Mbstatet&gt; const &amp;)"......
  </code></pre>