title: Multibyte CString to Unicode MFC
body: <p>I have 2 MFC  projects. </p>
  
  <p>A library project uses Multi-byte Character set.</p>
  
  <p>An executable project uses Unicode Character set.</p>
  
  <p>I only wrote the library project and have to use it in the executable. 
  One of the library's functions returns a CString. 
  When I try to put that CString into a variable in my unicode project and compile
  I get this:</p>
  
  <pre><code>Error 3 error LNK2001: unresolved external symbol "public: class  
  ATL::CStringT&lt;wchar_t,class StrTraitMFC_DLL&lt;wchar_t,class 
  ATL::ChTraitsCRT&lt;wchar_t&gt; &gt; &gt; __thiscall CTextDisplay::GetString(void)" 
  (?GetString@CTextDisplay@@QAE?AV?$CStringT@_WV?  $StrTraitMFC_DLL@_WV?
  $ChTraitsCRT@_W@ATL@@@@@ATL@@XZ)
  </code></pre>
  
  <p>I don't mind converting on any of the projects. I just want a way for the library to be able to return a string to the executable project.
  Switching either project to the other character set is not an option as they are both gigantic.</p>
  
  <p>Thanks in advance.</p>