| #![feature(box_patterns)] |
| #![feature(box_syntax)] |
| |
| struct HTMLImageData { |
| image: Option<String> |
| } |
| |
| struct ElementData { |
| kind: Box<ElementKind> |
| } |
| |
| enum ElementKind { |
| HTMLImageElement(HTMLImageData) |
| } |
| |
| enum NodeKind { |
| Element(ElementData) |
| } |
| |
| struct NodeData { |
| kind: Box<NodeKind>, |
| } |
| |
| fn main() { |
| let mut id = HTMLImageData { image: None }; |
| let ed = ElementData { kind: box ElementKind::HTMLImageElement(id) }; |
| let n = NodeData {kind : box NodeKind::Element(ed)}; |
| // n.b. span could be better |
| match n.kind { |
| box NodeKind::Element(ed) => match ed.kind { //~ ERROR non-exhaustive patterns |
| box ElementKind::HTMLImageElement(ref d) if d.image.is_some() => { true } |
| }, |
| }; |
| } |