title: Compiling C code in Visual Studio 2013 with complex.h library
body: <p><a href="http://blogs.msdn.com/b/vcblog/archive/2013/07/19/c99-library-support-in-visual-studio-2013.aspx" rel="noreferrer">http://blogs.msdn.com/b/vcblog/archive/2013/07/19/c99-library-support-in-visual-studio-2013.aspx</a></p>
  
  <p>C99 support added visual studio 2013, but I cant use complex.h in my "C" code.</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  #include &lt;complex.h&gt;
  int main(void)
  {
      double complex dc1 = 3 + 2 * I;
      double complex dc2 = 4 + 5 * I;
      double complex result;
  
      result = dc1 + dc2;
      printf(" ??? \n", result);
  
      return 0;
  }
  </code></pre>
  
  <p>I get syntax errors.</p>
  
  <p>Edit: Sorry for the missing part. </p>
  
  <pre><code>error C2146: syntax error : missing ';' before identifier 'dc1'
  error C2065: 'dc1' : undeclared identifier
  error C2088: '*' : illegal for struct
  error C2086: 'double complex' : redefinition
  error C2146: syntax error : missing ';' before identifier 'dc2'
  error C2065: 'dc2' : undeclared identifier
  error C2088: '*' : illegal for struct
  error C2086: 'double complex' : redefinition
  error C2146: syntax error : missing ';' before identifier 'result'
  error C2065: 'result' : undeclared identifier
  error C2065: 'result' : undeclared identifier
  error C2065: 'dc1' : undeclared identifier
  error C2065: 'dc2' : undeclared identifier
  error C2065: 'result' : undeclared identifier           
  IntelliSense: expected a ';'
  IntelliSense: expected a ';'
  IntelliSense: expected a ';'
  IntelliSense: identifier "result" is undefined
  IntelliSense: identifier "dc1" is undefined
  IntelliSense: identifier "dc2" is undefined
  </code></pre>