1 //! Support code for encoding and decoding types.
4 Core encoding and decoding interfaces.
8 use std::cell::{Cell, RefCell};
9 use std::marker::PhantomData;
18 fn emit_unit(&mut self) -> Result<(), Self::Error>;
19 fn emit_usize(&mut self, v: usize) -> Result<(), Self::Error>;
20 fn emit_u128(&mut self, v: u128) -> Result<(), Self::Error>;
21 fn emit_u64(&mut self, v: u64) -> Result<(), Self::Error>;
22 fn emit_u32(&mut self, v: u32) -> Result<(), Self::Error>;
23 fn emit_u16(&mut self, v: u16) -> Result<(), Self::Error>;
24 fn emit_u8(&mut self, v: u8) -> Result<(), Self::Error>;
25 fn emit_isize(&mut self, v: isize) -> Result<(), Self::Error>;
26 fn emit_i128(&mut self, v: i128) -> Result<(), Self::Error>;
27 fn emit_i64(&mut self, v: i64) -> Result<(), Self::Error>;
28 fn emit_i32(&mut self, v: i32) -> Result<(), Self::Error>;
29 fn emit_i16(&mut self, v: i16) -> Result<(), Self::Error>;
30 fn emit_i8(&mut self, v: i8) -> Result<(), Self::Error>;
31 fn emit_bool(&mut self, v: bool) -> Result<(), Self::Error>;
32 fn emit_f64(&mut self, v: f64) -> Result<(), Self::Error>;
33 fn emit_f32(&mut self, v: f32) -> Result<(), Self::Error>;
34 fn emit_char(&mut self, v: char) -> Result<(), Self::Error>;
35 fn emit_str(&mut self, v: &str) -> Result<(), Self::Error>;
39 fn emit_enum<F>(&mut self, _name: &str, f: F) -> Result<(), Self::Error>
41 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
46 fn emit_enum_variant<F>(
52 ) -> Result<(), Self::Error>
54 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
56 self.emit_usize(v_id)?;
61 fn emit_enum_variant_arg<F>(&mut self, _a_idx: usize, f: F) -> Result<(), Self::Error>
63 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
68 fn emit_enum_struct_variant<F>(
74 ) -> Result<(), Self::Error>
76 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
78 self.emit_enum_variant(v_name, v_id, len, f)
81 fn emit_enum_struct_variant_field<F>(
86 ) -> Result<(), Self::Error>
88 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
90 self.emit_enum_variant_arg(f_idx, f)
94 fn emit_struct<F>(&mut self, _name: &str, _len: usize, f: F) -> Result<(), Self::Error>
96 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
102 fn emit_struct_field<F>(
107 ) -> Result<(), Self::Error>
109 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
115 fn emit_tuple<F>(&mut self, _len: usize, f: F) -> Result<(), Self::Error>
117 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
123 fn emit_tuple_arg<F>(&mut self, _idx: usize, f: F) -> Result<(), Self::Error>
125 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
130 fn emit_tuple_struct<F>(&mut self, _name: &str, len: usize, f: F) -> Result<(), Self::Error>
132 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
134 self.emit_tuple(len, f)
137 fn emit_tuple_struct_arg<F>(&mut self, f_idx: usize, f: F) -> Result<(), Self::Error>
139 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
141 self.emit_tuple_arg(f_idx, f)
144 // Specialized types:
145 fn emit_option<F>(&mut self, f: F) -> Result<(), Self::Error>
147 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
149 self.emit_enum("Option", f)
153 fn emit_option_none(&mut self) -> Result<(), Self::Error> {
154 self.emit_enum_variant("None", 0, 0, |_| Ok(()))
157 fn emit_option_some<F>(&mut self, f: F) -> Result<(), Self::Error>
159 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
161 self.emit_enum_variant("Some", 1, 1, f)
164 fn emit_seq<F>(&mut self, len: usize, f: F) -> Result<(), Self::Error>
166 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
168 self.emit_usize(len)?;
173 fn emit_seq_elt<F>(&mut self, _idx: usize, f: F) -> Result<(), Self::Error>
175 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
180 fn emit_map<F>(&mut self, len: usize, f: F) -> Result<(), Self::Error>
182 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
184 self.emit_usize(len)?;
189 fn emit_map_elt_key<F>(&mut self, _idx: usize, f: F) -> Result<(), Self::Error>
191 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
197 fn emit_map_elt_val<F>(&mut self, _idx: usize, f: F) -> Result<(), Self::Error>
199 F: FnOnce(&mut Self) -> Result<(), Self::Error>,
209 fn read_nil(&mut self) -> Result<(), Self::Error>;
210 fn read_usize(&mut self) -> Result<usize, Self::Error>;
211 fn read_u128(&mut self) -> Result<u128, Self::Error>;
212 fn read_u64(&mut self) -> Result<u64, Self::Error>;
213 fn read_u32(&mut self) -> Result<u32, Self::Error>;
214 fn read_u16(&mut self) -> Result<u16, Self::Error>;
215 fn read_u8(&mut self) -> Result<u8, Self::Error>;
216 fn read_isize(&mut self) -> Result<isize, Self::Error>;
217 fn read_i128(&mut self) -> Result<i128, Self::Error>;
218 fn read_i64(&mut self) -> Result<i64, Self::Error>;
219 fn read_i32(&mut self) -> Result<i32, Self::Error>;
220 fn read_i16(&mut self) -> Result<i16, Self::Error>;
221 fn read_i8(&mut self) -> Result<i8, Self::Error>;
222 fn read_bool(&mut self) -> Result<bool, Self::Error>;
223 fn read_f64(&mut self) -> Result<f64, Self::Error>;
224 fn read_f32(&mut self) -> Result<f32, Self::Error>;
225 fn read_char(&mut self) -> Result<char, Self::Error>;
226 fn read_str(&mut self) -> Result<Cow<'_, str>, Self::Error>;
230 fn read_enum<T, F>(&mut self, _name: &str, f: F) -> Result<T, Self::Error>
232 F: FnOnce(&mut Self) -> Result<T, Self::Error>,
238 fn read_enum_variant<T, F>(&mut self, _names: &[&str], mut f: F) -> Result<T, Self::Error>
240 F: FnMut(&mut Self, usize) -> Result<T, Self::Error>,
242 let disr = self.read_usize()?;
247 fn read_enum_variant_arg<T, F>(&mut self, _a_idx: usize, f: F) -> Result<T, Self::Error>
249 F: FnOnce(&mut Self) -> Result<T, Self::Error>,
254 fn read_enum_struct_variant<T, F>(&mut self, names: &[&str], f: F) -> Result<T, Self::Error>
256 F: FnMut(&mut Self, usize) -> Result<T, Self::Error>,
258 self.read_enum_variant(names, f)
261 fn read_enum_struct_variant_field<T, F>(
266 ) -> Result<T, Self::Error>
268 F: FnOnce(&mut Self) -> Result<T, Self::Error>,
270 self.read_enum_variant_arg(f_idx, f)
274 fn read_struct<T, F>(&mut self, _s_name: &str, _len: usize, f: F) -> Result<T, Self::Error>
276 F: FnOnce(&mut Self) -> Result<T, Self::Error>,
282 fn read_struct_field<T, F>(
287 ) -> Result<T, Self::Error>
289 F: FnOnce(&mut Self) -> Result<T, Self::Error>,
295 fn read_tuple<T, F>(&mut self, _len: usize, f: F) -> Result<T, Self::Error>
297 F: FnOnce(&mut Self) -> Result<T, Self::Error>,
303 fn read_tuple_arg<T, F>(&mut self, _a_idx: usize, f: F) -> Result<T, Self::Error>
305 F: FnOnce(&mut Self) -> Result<T, Self::Error>,
310 fn read_tuple_struct<T, F>(&mut self, _s_name: &str, len: usize, f: F) -> Result<T, Self::Error>
312 F: FnOnce(&mut Self) -> Result<T, Self::Error>,
314 self.read_tuple(len, f)
317 fn read_tuple_struct_arg<T, F>(&mut self, a_idx: usize, f: F) -> Result<T, Self::Error>
319 F: FnOnce(&mut Self) -> Result<T, Self::Error>,
321 self.read_tuple_arg(a_idx, f)
324 // Specialized types:
325 fn read_option<T, F>(&mut self, mut f: F) -> Result<T, Self::Error>
327 F: FnMut(&mut Self, bool) -> Result<T, Self::Error>,
329 self.read_enum("Option", move |this| {
330 this.read_enum_variant(&["None", "Some"], move |this, idx| match idx {
333 _ => Err(this.error("read_option: expected 0 for None or 1 for Some")),
338 fn read_seq<T, F>(&mut self, f: F) -> Result<T, Self::Error>
340 F: FnOnce(&mut Self, usize) -> Result<T, Self::Error>,
342 let len = self.read_usize()?;
347 fn read_seq_elt<T, F>(&mut self, _idx: usize, f: F) -> Result<T, Self::Error>
349 F: FnOnce(&mut Self) -> Result<T, Self::Error>,
354 fn read_map<T, F>(&mut self, f: F) -> Result<T, Self::Error>
356 F: FnOnce(&mut Self, usize) -> Result<T, Self::Error>,
358 let len = self.read_usize()?;
363 fn read_map_elt_key<T, F>(&mut self, _idx: usize, f: F) -> Result<T, Self::Error>
365 F: FnOnce(&mut Self) -> Result<T, Self::Error>,
371 fn read_map_elt_val<T, F>(&mut self, _idx: usize, f: F) -> Result<T, Self::Error>
373 F: FnOnce(&mut Self) -> Result<T, Self::Error>,
379 fn error(&mut self, err: &str) -> Self::Error;
382 pub trait Encodable<S: Encoder> {
383 fn encode(&self, s: &mut S) -> Result<(), S::Error>;
386 pub trait Decodable<D: Decoder>: Sized {
387 fn decode(d: &mut D) -> Result<Self, D::Error>;
390 impl<S: Encoder> Encodable<S> for usize {
391 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
396 impl<D: Decoder> Decodable<D> for usize {
397 fn decode(d: &mut D) -> Result<usize, D::Error> {
402 impl<S: Encoder> Encodable<S> for u8 {
403 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
408 impl<D: Decoder> Decodable<D> for u8 {
409 fn decode(d: &mut D) -> Result<u8, D::Error> {
414 impl<S: Encoder> Encodable<S> for u16 {
415 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
420 impl<D: Decoder> Decodable<D> for u16 {
421 fn decode(d: &mut D) -> Result<u16, D::Error> {
426 impl<S: Encoder> Encodable<S> for u32 {
427 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
432 impl<D: Decoder> Decodable<D> for u32 {
433 fn decode(d: &mut D) -> Result<u32, D::Error> {
438 impl<S: Encoder> Encodable<S> for ::std::num::NonZeroU32 {
439 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
440 s.emit_u32(self.get())
444 impl<D: Decoder> Decodable<D> for ::std::num::NonZeroU32 {
445 fn decode(d: &mut D) -> Result<Self, D::Error> {
446 d.read_u32().map(|d| ::std::num::NonZeroU32::new(d).unwrap())
450 impl<S: Encoder> Encodable<S> for u64 {
451 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
456 impl<D: Decoder> Decodable<D> for u64 {
457 fn decode(d: &mut D) -> Result<u64, D::Error> {
462 impl<S: Encoder> Encodable<S> for u128 {
463 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
468 impl<D: Decoder> Decodable<D> for u128 {
469 fn decode(d: &mut D) -> Result<u128, D::Error> {
474 impl<S: Encoder> Encodable<S> for isize {
475 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
480 impl<D: Decoder> Decodable<D> for isize {
481 fn decode(d: &mut D) -> Result<isize, D::Error> {
486 impl<S: Encoder> Encodable<S> for i8 {
487 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
492 impl<D: Decoder> Decodable<D> for i8 {
493 fn decode(d: &mut D) -> Result<i8, D::Error> {
498 impl<S: Encoder> Encodable<S> for i16 {
499 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
504 impl<D: Decoder> Decodable<D> for i16 {
505 fn decode(d: &mut D) -> Result<i16, D::Error> {
510 impl<S: Encoder> Encodable<S> for i32 {
511 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
516 impl<D: Decoder> Decodable<D> for i32 {
517 fn decode(d: &mut D) -> Result<i32, D::Error> {
522 impl<S: Encoder> Encodable<S> for i64 {
523 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
528 impl<D: Decoder> Decodable<D> for i64 {
529 fn decode(d: &mut D) -> Result<i64, D::Error> {
534 impl<S: Encoder> Encodable<S> for i128 {
535 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
540 impl<D: Decoder> Decodable<D> for i128 {
541 fn decode(d: &mut D) -> Result<i128, D::Error> {
546 impl<S: Encoder> Encodable<S> for str {
547 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
552 impl<S: Encoder> Encodable<S> for &str {
553 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
558 impl<S: Encoder> Encodable<S> for String {
559 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
560 s.emit_str(&self[..])
564 impl<D: Decoder> Decodable<D> for String {
565 fn decode(d: &mut D) -> Result<String, D::Error> {
566 Ok(d.read_str()?.into_owned())
570 impl<S: Encoder> Encodable<S> for f32 {
571 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
576 impl<D: Decoder> Decodable<D> for f32 {
577 fn decode(d: &mut D) -> Result<f32, D::Error> {
582 impl<S: Encoder> Encodable<S> for f64 {
583 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
588 impl<D: Decoder> Decodable<D> for f64 {
589 fn decode(d: &mut D) -> Result<f64, D::Error> {
594 impl<S: Encoder> Encodable<S> for bool {
595 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
600 impl<D: Decoder> Decodable<D> for bool {
601 fn decode(d: &mut D) -> Result<bool, D::Error> {
606 impl<S: Encoder> Encodable<S> for char {
607 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
612 impl<D: Decoder> Decodable<D> for char {
613 fn decode(d: &mut D) -> Result<char, D::Error> {
618 impl<S: Encoder> Encodable<S> for () {
619 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
624 impl<D: Decoder> Decodable<D> for () {
625 fn decode(d: &mut D) -> Result<(), D::Error> {
630 impl<S: Encoder, T> Encodable<S> for PhantomData<T> {
631 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
636 impl<D: Decoder, T> Decodable<D> for PhantomData<T> {
637 fn decode(d: &mut D) -> Result<PhantomData<T>, D::Error> {
643 impl<D: Decoder, T: Decodable<D>> Decodable<D> for Box<[T]> {
644 fn decode(d: &mut D) -> Result<Box<[T]>, D::Error> {
645 let v: Vec<T> = Decodable::decode(d)?;
646 Ok(v.into_boxed_slice())
650 impl<S: Encoder, T: Encodable<S>> Encodable<S> for Rc<T> {
651 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
656 impl<D: Decoder, T: Decodable<D>> Decodable<D> for Rc<T> {
657 fn decode(d: &mut D) -> Result<Rc<T>, D::Error> {
658 Ok(Rc::new(Decodable::decode(d)?))
662 impl<S: Encoder, T: Encodable<S>> Encodable<S> for [T] {
663 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
664 s.emit_seq(self.len(), |s| {
665 for (i, e) in self.iter().enumerate() {
666 s.emit_seq_elt(i, |s| e.encode(s))?
673 impl<S: Encoder, T: Encodable<S>> Encodable<S> for Vec<T> {
674 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
675 s.emit_seq(self.len(), |s| {
676 for (i, e) in self.iter().enumerate() {
677 s.emit_seq_elt(i, |s| e.encode(s))?
684 impl<D: Decoder, T: Decodable<D>> Decodable<D> for Vec<T> {
685 fn decode(d: &mut D) -> Result<Vec<T>, D::Error> {
686 d.read_seq(|d, len| {
687 let mut v = Vec::with_capacity(len);
689 v.push(d.read_seq_elt(i, |d| Decodable::decode(d))?);
696 impl<S: Encoder> Encodable<S> for [u8; 20] {
697 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
698 s.emit_seq(self.len(), |s| {
699 for (i, e) in self.iter().enumerate() {
700 s.emit_seq_elt(i, |s| e.encode(s))?
707 impl<D: Decoder> Decodable<D> for [u8; 20] {
708 fn decode(d: &mut D) -> Result<[u8; 20], D::Error> {
709 d.read_seq(|d, len| {
711 let mut v = [0u8; 20];
713 v[i] = d.read_seq_elt(i, |d| Decodable::decode(d))?;
720 impl<'a, S: Encoder, T: Encodable<S>> Encodable<S> for Cow<'a, [T]>
722 [T]: ToOwned<Owned = Vec<T>>,
724 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
725 s.emit_seq(self.len(), |s| {
726 for (i, e) in self.iter().enumerate() {
727 s.emit_seq_elt(i, |s| e.encode(s))?
734 impl<D: Decoder, T: Decodable<D> + ToOwned> Decodable<D> for Cow<'static, [T]>
736 [T]: ToOwned<Owned = Vec<T>>,
738 fn decode(d: &mut D) -> Result<Cow<'static, [T]>, D::Error> {
739 d.read_seq(|d, len| {
740 let mut v = Vec::with_capacity(len);
742 v.push(d.read_seq_elt(i, |d| Decodable::decode(d))?);
749 impl<S: Encoder, T: Encodable<S>> Encodable<S> for Option<T> {
750 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
751 s.emit_option(|s| match *self {
752 None => s.emit_option_none(),
753 Some(ref v) => s.emit_option_some(|s| v.encode(s)),
758 impl<D: Decoder, T: Decodable<D>> Decodable<D> for Option<T> {
759 fn decode(d: &mut D) -> Result<Option<T>, D::Error> {
760 d.read_option(|d, b| if b { Ok(Some(Decodable::decode(d)?)) } else { Ok(None) })
764 impl<S: Encoder, T1: Encodable<S>, T2: Encodable<S>> Encodable<S> for Result<T1, T2> {
765 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
766 s.emit_enum("Result", |s| match *self {
768 s.emit_enum_variant("Ok", 0, 1, |s| s.emit_enum_variant_arg(0, |s| v.encode(s)))
771 s.emit_enum_variant("Err", 1, 1, |s| s.emit_enum_variant_arg(0, |s| v.encode(s)))
777 impl<D: Decoder, T1: Decodable<D>, T2: Decodable<D>> Decodable<D> for Result<T1, T2> {
778 fn decode(d: &mut D) -> Result<Result<T1, T2>, D::Error> {
779 d.read_enum("Result", |d| {
780 d.read_enum_variant(&["Ok", "Err"], |d, disr| match disr {
781 0 => Ok(Ok(d.read_enum_variant_arg(0, |d| T1::decode(d))?)),
782 1 => Ok(Err(d.read_enum_variant_arg(0, |d| T2::decode(d))?)),
785 "Encountered invalid discriminant while \
795 ($name:ident, $($other:ident,)*) => (tuple! { $($other,)* })
798 /// Evaluates to the number of tokens passed to it.
800 /// Logarithmic counting: every one or two recursive expansions, the number of
801 /// tokens to count is divided by two, instead of being reduced by one.
802 /// Therefore, the recursion depth is the binary logarithm of the number of
803 /// tokens to count, and the expanded tree is likewise very small.
806 ($one:tt) => (1usize);
807 ($($pairs:tt $_p:tt)*) => (count!($($pairs)*) << 1usize);
808 ($odd:tt $($rest:tt)*) => (count!($($rest)*) | 1usize);
813 ( $($name:ident,)+ ) => (
814 impl<D: Decoder, $($name: Decodable<D>),+> Decodable<D> for ($($name,)+) {
815 #[allow(non_snake_case)]
816 fn decode(d: &mut D) -> Result<($($name,)+), D::Error> {
817 let len: usize = count!($($name)+);
818 d.read_tuple(len, |d| {
820 let ret = ($(d.read_tuple_arg({ i+=1; i-1 }, |d| -> Result<$name, D::Error> {
827 impl<S: Encoder, $($name: Encodable<S>),+> Encodable<S> for ($($name,)+) {
828 #[allow(non_snake_case)]
829 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
830 let ($(ref $name,)+) = *self;
832 $(let $name = $name; n += 1;)+
833 s.emit_tuple(n, |s| {
835 $(s.emit_tuple_arg({ i+=1; i-1 }, |s| $name.encode(s))?;)+
844 tuple! { T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, }
846 impl<S: Encoder> Encodable<S> for path::Path {
847 fn encode(&self, e: &mut S) -> Result<(), S::Error> {
848 self.to_str().unwrap().encode(e)
852 impl<S: Encoder> Encodable<S> for path::PathBuf {
853 fn encode(&self, e: &mut S) -> Result<(), S::Error> {
854 path::Path::encode(self, e)
858 impl<D: Decoder> Decodable<D> for path::PathBuf {
859 fn decode(d: &mut D) -> Result<path::PathBuf, D::Error> {
860 let bytes: String = Decodable::decode(d)?;
861 Ok(path::PathBuf::from(bytes))
865 impl<S: Encoder, T: Encodable<S> + Copy> Encodable<S> for Cell<T> {
866 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
871 impl<D: Decoder, T: Decodable<D> + Copy> Decodable<D> for Cell<T> {
872 fn decode(d: &mut D) -> Result<Cell<T>, D::Error> {
873 Ok(Cell::new(Decodable::decode(d)?))
878 // Should use `try_borrow`, returning a
879 // `encoder.error("attempting to Encode borrowed RefCell")`
880 // from `encode` when `try_borrow` returns `None`.
882 impl<S: Encoder, T: Encodable<S>> Encodable<S> for RefCell<T> {
883 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
884 self.borrow().encode(s)
888 impl<D: Decoder, T: Decodable<D>> Decodable<D> for RefCell<T> {
889 fn decode(d: &mut D) -> Result<RefCell<T>, D::Error> {
890 Ok(RefCell::new(Decodable::decode(d)?))
894 impl<S: Encoder, T: Encodable<S>> Encodable<S> for Arc<T> {
895 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
900 impl<D: Decoder, T: Decodable<D>> Decodable<D> for Arc<T> {
901 fn decode(d: &mut D) -> Result<Arc<T>, D::Error> {
902 Ok(Arc::new(Decodable::decode(d)?))
906 impl<S: Encoder, T: ?Sized + Encodable<S>> Encodable<S> for Box<T> {
907 fn encode(&self, s: &mut S) -> Result<(), S::Error> {
911 impl<D: Decoder, T: Decodable<D>> Decodable<D> for Box<T> {
912 fn decode(d: &mut D) -> Result<Box<T>, D::Error> {
913 Ok(box Decodable::decode(d)?)