title: xcode 4.5.2 cannot build simple c++ project (iosfwd)
body: <p>I have upgraded Xcode to 4.5.2
  I have created simple c++ project and haven't change any thing.
  There is only one file main.cpp with following code</p>
  
  <pre><code>#include &lt;iostream&gt;
  
  int main(int argc, const char * argv[])
  {
  
  // insert code here...
  std::cout &lt;&lt; "Hello, World!\n";
  return 0;
  }
  </code></pre>
  
  <p>but when I build project I get one error
  In file iosfwd </p>
  
  <pre><code>In file included from /Users/abhineet/Github/Wiretap/Wiretap/main.cpp:9:
  In file included from   /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/ c++/v1/iostream:38:
  In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/ios:215:
  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/iosfwd:90:10: fatal error: 'wchar.h' file not found
  </code></pre>
  
  <p>I dont know why I'm getting this error
  but when I run it in Xcode 4.5, there is no error</p>