912     pub kind: ClassSet,
922 pub enum ClassSet {  enum
930 impl ClassSet {  implementation
932     pub fn union(ast: ClassSetUnion) -> ClassSet {  in union()  argument
933         ClassSet::Item(ClassSetItem::Union(ast))  in union()
939             ClassSet::Item(ref x) => x.span(),  in span()
940             ClassSet::BinaryOp(ref x) => &x.span,  in span()
947             ClassSet::Item(ClassSetItem::Empty(_)) => true,  in is_empty()
1069     pub lhs: Box<ClassSet>,
1071     pub rhs: Box<ClassSet>,
1409 impl Drop for ClassSet {  implementation
1414             ClassSet::Item(ref item) => match *item {  in drop()
1432             ClassSet::BinaryOp(ref op) => {  in drop()
1440         let empty_set = || ClassSet::Item(ClassSetItem::Empty(empty_span()));  in drop()
1444                 ClassSet::Item(ref mut item) => match *item {  in drop()
1455                         stack.extend(x.items.drain(..).map(ClassSet::Item));  in drop()
1458                 ClassSet::BinaryOp(ref mut op) => {  in drop()