Default value for vector valued boost::program_options
<p>I have a boost::program_options option that successfully parses the desired input options into a vector, but I'm not seeing how to also give it a default value. Example:</p>

<pre><code>base.add_options()
 ("vector_value",po::value&lt;std::vector&lt;double&gt; &gt;(&amp;vecoption)-&gt;multitoken(),"description");
</code></pre>

<p>works fine to read values into vecoptions, and something like</p>

<pre><code>    base.add_options()
 ("int_value",po::value&lt;int&gt;(&amp;intoption)-&gt;default_value(1),"description");
</code></pre>

<p>also works fine, but trying to give the vector argument a default value like in </p>

<pre><code>base.add_options()
 ("vector_value",po::value&lt;std::vector&lt;double&gt; &gt;(&amp;vecoption)-&gt;default_value(std::vector&lt;double&gt;{0,1,2}),"description");
</code></pre>

<p>gives a compiler error</p>

<blockquote>
  <p>error: static assertion failed: Source type is neither std::ostream`able nor std::wostream`able</p>
</blockquote>

<p>How can I create a vector-valued float option with default values like {0,1,2}?</p>