title: How can I parse nested arrays?
body: <p>I have a JSON that looks like:</p>
  
  <pre><code>  "results": [
      {
        "plate": "FRJ7248",
        "confidence": 94.583724975586,
        "matches_template": 1,
        "plate_index": 0,
        "region": "us-ny",
        "region_confidence": 88,
        "processing_time_ms": 94.328330993652,
        "requested_topn": 25,
        "coordinates": [
          {
            "x": 1545,
            "y": 233
          },
          {
            "x": 1640,
            "y": 241
          },
  ...
  ...
  </code></pre>
  
  <p>and I'm wondering how I parse the <code>coordinates</code> array, I've tried the following:</p>
  
  <pre><code>BOOST_FOREACH(boost::property_tree::ptree::value_type&amp; v, pt.get_child("results")) {
      ptree subtree1 = v.second.get&lt;string&gt;;
      BOOST_FOREACH(boost::property_tree::ptree::value_type&amp; w, subtree1) {
          LOG_NS_INFO &lt;&lt; "OpenALPR     X  " &lt;&lt; w.second.get&lt;string&gt;("x");
          LOG_NS_INFO &lt;&lt; "OpenALPR     Y  " &lt;&lt; w.second.get&lt;string&gt;("y");
      }
  }
  </code></pre>
  
  <p>but got</p>
  
  <pre><code>error: conversion from ‘&lt;unresolved overloaded function type&gt;’ to non-scalar type ‘boost::property_tree::ptree {aka boost::property_tree::basic_ptree&lt;std::__cxx11::basic_string&lt;char&gt;, std::__cxx11::basic_string&lt;char&gt; &gt;}’ requested
               ptree subtree1 = v.second.get&lt;string&gt;;
  </code></pre>
  
  <p>how can I fix this?</p>