title: force to compile a specific file as Objective-C/file type, but the entire project as Objective-C++
body: <p>I'm adding some features to a project that already exist. It works as expected.</p>
  
  <p>Then I added few files from an open library to that project. </p>
  
  <p>Now, Xcode fails to compile the whole project. </p>
  
  <p>Investigating why, I found out that the problem is the "Compile source as" flag, it is set by default to "Objective-C++".</p>
  
  <p>Switching that flag to other value makes Xcode to complain. Hundreds of errors in any case.
  I have the idea the previous dev did this to avoid renaming .c, .cpp, .m to .mm. He is not here anymore. So, hard to say.</p>
  
  <p>Any idea how to solve this?
  I see few options:  </p>
  
  <ol>
  <li>Either I rename the files as necessary. Which means hundreds of
  files renamed. Or  </li>
  <li>I force Xcode to compile a specific file as
  Objective-C/file type, but the entire project as Objective-C++ Or</li>
  <li>I create a small project, and then produce a shared library.</li>
  </ol>
  
  <p>I would like to continue with option 2. Is it possible? and how?</p>
  
  <p>Any other idea?</p>
  
  <p>Thanks</p>