title: Extern C functions in Objective-c
body: <p>i develop iPhone apps, and after updating to sdk 3.0, I get an error on CFWriteStreamCreateWithFTPURL while linking. This is the code I call to get the error.</p>
  
  <pre><code>streamInfo.writeStream = CFWriteStreamCreateWithFTPURL(NULL, urlRefWrite);
  </code></pre>
  
  <p>I have an idea that it can be solved using extern "C", but after having googled it, I have not found the solution to my problem. Any ideas?</p>
  
  <p>Thanks in advance</p>