The excerpt below is from http://www.gtkmm.org/docs/gtkmm-2.4/docs/reference/html/classGtk_1_1Dialog.html
Something is going wrong with the page generation, as it appears to be mixing HTML with the code.

 <tt>int</tt> result = dialog.run();
 switch (result)
 {
 case GTK_RESPONSE_ACCEPT:
 do_application_specific_something (&lt;!-- --&gt;);
 break;
 default:
 do_nothing_since_dialog_was_cancelled (&lt;!-- --&gt;);
 break;
 }