Function xmlAddAttributeDecl 

pub unsafe extern "C" fn xmlAddAttributeDecl(
    ctxt: *mut xmlValidCtxt,
    dtd: *mut xmlDtd,
    elem: *const xmlChar,
    name: *const xmlChar,
    ns: *const xmlChar,
    type_: xmlAttributeType,
    def: xmlAttributeDefault,
    defaultValue: *const xmlChar,
    tree: *mut xmlEnumeration,
) -> *mut xmlAttribute