Hello *,<br><br>I would like to ask the developers of boost::any if the ctor template in boost::any<br><br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; template&lt;typename ValueType&gt;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; any(const ValueType &amp; value)<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; : content(new holder&lt;ValueType&gt;(value))<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; {<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br><br><br>is intentionally not marked as explicit. Today using boost::any_cast and with a std::map (mapping of some id to boost::any) iterator I was wondering why I got an exception when I found a correct any instance.<br>
<br><br>My code looked like:<br><br>map_type::const_iterator&nbsp; iter = map.find(Key);<br>if(map.end()!=iter)<br>&nbsp;&nbsp; return boost::any_cast&lt;SomeResultType const&amp;&gt;(*iter);<br><br><br>Unforturenately, I forgot that map iterator references a pair&lt;KeyType, ValueType&gt;. This cast caused the compiler to implicitly create a new const any type containing the dereferenced pair and throw an exception that my expected result type was wrong. I don&#39;t know which design rationale was intended when this ctor was not marked as explicit or if it is a bug.<br>
<br><br><br>With Kind Regards,<br>Ovanes<br><br><br><br>BTW, I use boost 1.34.1 and vc 7.1.<br>