Add support for Encode and Decode of Pin<Box<T>>

Author: nixpulvis

src/derive/impls.rs

@@ -5,13 +5,15 @@ use crate::derive::empty::EmptyCoder;
 use crate::derive::map::{MapDecoder, MapEncoder};
 use crate::derive::option::{OptionDecoder, OptionEncoder};
 use crate::derive::result::{ResultDecoder, ResultEncoder};
-use crate::derive::smart_ptr::{DerefEncoder, FromDecoder};
+use crate::derive::smart_ptr::{DerefEncoder, FromDecoder, PinDecoder, PinEncoder};
+use core::ops::Deref;
 use crate::derive::vec::{VecDecoder, VecEncoder};
 use crate::derive::{Decode, Encode};
 use crate::f32::{F32Decoder, F32Encoder};
 use crate::int::{CheckedIntDecoder, IntDecoder, IntEncoder};
 use crate::str::{StrDecoder, StrEncoder};
 use alloc::collections::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};
+use core::pin::Pin;
 use alloc::string::String;
 use alloc::vec::Vec;
 use core::marker::PhantomData;
@@ -111,6 +113,19 @@ impl_smart_ptr!(::alloc::rc::Rc);
 #[cfg(target_has_atomic = "ptr")]
 impl_smart_ptr!(::alloc::sync::Arc);
 
+impl<P: Deref + Encode> Encode for Pin<P>
+where
+    P::Target: Encode,
+{
+    type Encoder = PinEncoder<P>;
+}
+impl<'a, P: Deref + Decode<'a>> Decode<'a> for Pin<P>
+where
+    Pin<P>: From<P>,
+{
+    type Decoder = PinDecoder<'a, P>;
+}
+
 impl<T: Encode, const N: usize> Encode for [T; N] {
     type Encoder = ArrayEncoder<T, N>;
 }

src/derive/smart_ptr.rs

@@ -52,11 +52,15 @@ impl<'a, F: From<T>, T: Decode<'a>> Decoder<'a, F> for FromDecoder<'a, T> {
     }
 }
 
+pub type PinEncoder<P> = DerefEncoder<<P as Deref>::Target>;
+pub type PinDecoder<'a, P> = FromDecoder<'a, P>;
+
 #[cfg(test)]
 mod tests {
     use crate::{decode, encode};
     use alloc::boxed::Box;
     use alloc::string::ToString;
+    use core::pin::Pin;
 
     #[test]
     fn box_() {
@@ -75,4 +79,10 @@ mod tests {
         let v = "box".to_string().into_boxed_str();
         assert_eq!(decode::<Box<str>>(&encode(&v)).unwrap(), v);
     }
+
+    #[test]
+    fn pin_box_i32() {
+        let v = Box::pin(7i32);
+        assert_eq!(decode::<Pin<Box<i32>>>(&encode(&v)).unwrap(), v);
+    }
 }