1 //! Utilities to support "extension" fields.
2 //!
3 //! Extensions are [described in the official protobuf documentation][exts].
4 //!
5 //! [exts]: https://developers.google.com/protocol-buffers/docs/proto#extensions
6 
7 use std::marker::PhantomData;
8 
9 use core::Message;
10 use types::ProtobufType;
11 
12 /// Optional ext field
13 pub struct ExtFieldOptional<M: Message, T: ProtobufType> {
14     /// Extension field number
15     pub field_number: u32,
16     /// Marker
17     // TODO: hide
18     pub phantom: PhantomData<(M, T)>,
19 }
20 
21 /// Repeated ext field
22 pub struct ExtFieldRepeated<M: Message, T: ProtobufType> {
23     /// Extension field number
24     pub field_number: u32,
25     /// Extension field number
26     // TODO: hide
27     pub phantom: PhantomData<(M, T)>,
28 }
29 
30 impl<M: Message, T: ProtobufType> ExtFieldOptional<M, T> {
31     /// Get a copy of value from a message.
32     ///
33     /// Extension data is stored in [`UnknownFields`](crate::UnknownFields).
get(&self, m: &M) -> Option<T::Value>34     pub fn get(&self, m: &M) -> Option<T::Value> {
35         m.get_unknown_fields()
36             .get(self.field_number)
37             .and_then(T::get_from_unknown)
38     }
39 }
40 
41 impl<M: Message, T: ProtobufType> ExtFieldRepeated<M, T> {
42     /// Get a copy of value from a message (**not implemented**).
get(&self, _m: &M) -> Vec<T::Value>43     pub fn get(&self, _m: &M) -> Vec<T::Value> {
44         // TODO
45         unimplemented!()
46     }
47 }
48