export class rule
<p>recently i have been wondering why we can use mfc's class while it seems not to export its classes,    cause i know we can export a class using  __declspec(dllimport),for example:
i define a class CBaseClass in a dll named test.dll,then i use it as a base class in my test.exe;before i can use CBaseClass i should first export it from test.dll;so i think that ruld should apply to mfc;but i don't see that anywhere in mfc's source code ,anyboy can shed a light on this ,thanks </p>

<pre><code>class CWnd:public CCmdTarget
{
}
</code></pre>

<p>there is no __declspec(dllimport),they why can we use it in our project</p>
