The <cxxUnionTemplateParameter> element describes a union parameter.
One or more <cxxUnionTemplateParameter> elements reside within the <cxxUnionTemplateParameters> container. <cxxUnionTemplateParameter> requires the child element <cxxUnionTemplateParameterType>; that describes the type of parameter. <cxxUnionTemplateParameter> may also contain the child element <apiDefNote> to describe the parameter further.
apiDefNote, cxxUnionTemplateParameterType
(cxxUnionTemplateParameterType then apiDefNote, )