https://svn.boost.org/trac10/ticket/12772 <p> Stream operators for intervals only work for std::string, e.g. the following code gives a compilation error: </p> <pre class="wiki">void Test() { typedef boost::icl::interval_set&lt;int&gt; IntervalSet; IntervalSet setSimple; setSimple.add(1).add(3); for (const IntervalSet::value_type&amp; r : setSimple) { std::wstringstream wsstr; wsstr &lt;&lt; r; } } </pre> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/12772 Trac 1.4.3