title: Getting YAML::TypedBadConversion when trying to read string value with yaml-cpp
body: <p>I have been having a error that I can't figure out why a getting it. When trying to read the following file <code>example.yaml</code>:</p>
  <pre><code>BFS_power:
    graph: power.graph
    type: METIS
  BFS_avg:
    graph: DEFAULT
    type: whatever
  </code></pre>
  <p>With the following minimal example:</p>
  <pre><code>YAML:Node Instances = YAML::LoadFile(instancesFile);
  std::cout &lt;&lt; Instances[&quot;BFS_power&quot;][&quot;graph&quot;].as&lt;std::string&gt;() &lt;&lt; std::endl;
  </code></pre>
  <p>Causes following error:</p>
  <pre><code>terminate called after throwing an instance of 'YAML::TypedBadConversion&lt;std::__cxx11::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt; &gt; &gt;'
    what():  bad conversion
  </code></pre>
  <p>Doing <code>std::cout &lt;&lt; Instances[&quot;BFS_power&quot;][&quot;graph&quot;] &lt;&lt; std::endl;</code> will print the correct value of <code>power.graph</code>, so I know that the file is being read. However, the object resulting from <code>Instances[&quot;BFS_power&quot;][&quot;graph&quot;]</code> is Node not a string.</p>
  <p>Is there something that I am missing that is necessary to read strings?</p>