https://svn.boost.org/trac10/ticket/13631 <pre class="wiki"> Examples Without: void my_function ( boost::property_tree:ptree &amp;p , std::pair&lt; Here goes long story about I don't know what. Shoud I use asoc_iter or cons_assoc or decltyp and How. Blah, blah. Help! Help! &gt; &amp;r , std::string const &amp; name ) { r = p.equal_range( name ); } With: void my_function ( boost::property_tree:ptree const&amp;p , boost::property_tree:ptree::range_const_type &amp;r , std::string const &amp; name ) { r = p.equal_range( name ); } </pre> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/13631 Trac 1.4.3