title: Compile errors with #include <string> in Cocoa App
body: <p>I am trying to compile a Cocoa app in xcode 4.0 and I'm getting this error...</p>
  
  <pre><code>fatal error: 'string' file not found
  </code></pre>
  
  <p>...when trying to compile to .pch file on this line:</p>
  
  <pre><code>#include &lt;string&gt;
  </code></pre>
  
  <p>I have another xcode project that does the same thing, but does not get the error.  I have scoured the build settings for some different, but I can't find one.  The only difference is that the project that compiles OK was started as a command line project, not a Cocoa project, but the build setting are the same.</p>
  
  <p>The target OS is Mac OS X 10.6</p>
  
  <p>The error happens when compiling the precompiled header and doesn't get to any of the other files.  The only framework that the compiling version has is Foundation.framework and the non-compiling one has it as well.</p>
  
  <p>Why is it not finding  in one project and not the other?  Any advice?</p>