title: Undefined symbols for architecture in static library (OGDF)
body: <p>I'm using Xcode to add <a href="http://www.ogdf.net/" rel="nofollow noreferrer">OGDF</a> to my C++ project. It's a static .a library, and after compiling it from sources, i've successfully add it to compile sources, set the right search paths, and everything goes right until i include for, example,<code>"ogdf/basic/Graph.h"</code>.
  When i try to build with this include, linker gives me errors on the library inner files, saying there's no standart functions, like <code>"std::cout",</code> or <code>std::basic_ostream&lt;char, std::char_traits&lt;char&gt; &gt;&amp; std::endl&lt;char, std::char_traits&lt;char&gt; &gt;(std::basic_ostream&lt;char, std::char_traits&lt;char&gt; &gt;&amp;)</code>.</p>
  
  <p>It looks like this:
  <img src="https://i.stack.imgur.com/cXaot.png" alt="enter image description here">
  It's strange, since i believe such functions exists and i don't believe that OGDF developers have any mistakes in their code.
  So what in fact could cause this errors?</p>