title: What is wrong on <boost/program_options/options_description.hpp>?
body: <p>I need help on , I have been doing this on the same computer, it means I already installed boost library, and based on the previous code, but this time it gives me errors: 
  /tmp/ccpAYzPw.o: In function `main':</p>
  
  <pre><code>reading_data.cpp:(.text+0x356): undefined reference to `boost::program_options::options_description::m_default_line_length'
  reading_data.cpp:(.text+0x361): undefined reference to `boost::program_options::options_description::m_default_line_length'
  reading_data.cpp:(.text+0x3a6): undefined reference to `boost::program_options::options_description::options_description(std::__cxx11::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt; &gt; const&amp;, unsigned int, unsigned int)'
  reading_data.cpp:(.text+0x3d3): undefined reference to `boost::program_options::options_description::add_options()'
  collect2: error: ld returned 1 exit status
  &lt;builtin&gt;: recipe for target 'reading_data' failed
  </code></pre>
  
  <p>I spent almost 2 hour to see what is going on? but I could not understand why, so I need  your helps.</p>
  
  <p>Here is my code and thank you very much.</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  #include &lt;stdlib.h&gt;
  #include &lt;iostream&gt;
  #include &lt;fstream&gt;      // std::ifstream
  #include &lt;boost/program_options.hpp&gt;
  
  int main ()
  {
      boost::program_options::options_description desc("Allowed options");
  
      desc.add_options()
              ("sign"  , program_options::value&lt;string&gt;()  -&gt; default_value("gbm")    ,"name of the input")
              ("week"  , program_options::value&lt;double&gt;()  -&gt; default_value(1930)     ,"number of the week")
              ("day"   , program_options::value&lt;double&gt;()  -&gt; default_value(0)        ,"number of the day in within the week")
              ("hour"  , program_options::value&lt;double&gt;()  -&gt; default_value(0)        ,"time in hour")
              ("minute", program_options::value&lt;double&gt;()  -&gt; default_value(0)        ,"time in minute")
              ("second", program_options::value&lt;double&gt;()  -&gt; default_value(0)        ,"time in second")
              ;
  
      cout &lt;&lt; "Done!" &lt;&lt; endl;
      return 0;
  }
  </code></pre>