Function xmlAddAttributeDecl 

pub unsafe extern "C" fn xmlAddAttributeDecl(
    ctxt: xmlValidCtxtPtr,
    dtd: xmlDtdPtr,
    elem: *const xmlChar,
    name: *const xmlChar,
    ns: *const xmlChar,
    type_: xmlAttributeType,
    def: xmlAttributeDefault,
    defaultValue: *const xmlChar,
    tree: xmlEnumerationPtr,
) -> xmlAttributePtr