title: Visual Studio 2015 IntelliSense in .cpp files #included as headers
body: <p>In my project I have a main cpp file and any other files are excluded from the build and I include them from the main cpp file to create one translation unit. This worked perfectly in VS 2013 however I am having issues in 2015 where any cpp files that are not included in the build display types defined in other cpp files with red errors. The project builds fine and I can F12 to the type definitions, but the types do not appear in intellisense and are displayed as errors.</p>
  
  <p>Does anyone know if this is a known issue or can any else replicate it - or is it something specific to my setup?</p>
  
  <p>For example I have main.cpp</p>
  
  <pre><code>struct Foo
  {
      int Bar;
  };
  
  #include "Test.cpp"
  
  int main()
  {
      Foo x = Test();
  
      return 0;
  }
  </code></pre>
  
  <p>And Test.cpp which is exclude from the build using VS UI.</p>
  
  <pre><code>Foo Test()
  {
      Foo x;
      x.Bar = 2;
      return x;
  }
  </code></pre>
  
  <p>This builds but intellisense won't display Foo from Test.cpp and will display red errors under Foo.</p>