The <cxxClassDerivationVirtual> element indicates if inheritance is declared as virtual.
The <cxxClassDerivationVirtual> element is contained within a <cxxClassDerivation> element. The name attribute must be set to virtual and the value attribute must be set to true. The base referered to by the <cxxClassDerivationVirtual> element is indicated by using either a <cxxClassBaseClass>, <cxxClassBaseStruct> or <cxxClassBaseUnion> element as a sibling of <cxxClassDerivationVirtual>.
<cxxClassDerivation>
<cxxClassDerivationVirtual name="virtual" value="true"/>
<cxxClassDerivationAccessSpecifier value="public"/>
<cxxClassBaseClass href="class_base">Base</cxxClassBaseClass>
</cxxClassDerivation>