WIP

Author: pitdicker

rand_core/src/impls.rs

@@ -184,8 +184,9 @@ pub fn next_u64_via_fill<R: RngCore + ?Sized>(rng: &mut R) -> u64 {
 /// [`RngCore`]: ../RngCore.t.html
 /// [`SeedableRng`]: ../SeedableRng.t.html
 #[derive(Clone)]
-#[cfg_attr(feature="serde-1", derive(Serialize,Deserialize))]
+#[cfg_attr(feature="serde-1", derive(Serialize))]
 pub struct BlockRng<R: BlockRngCore + ?Sized> {
+    #[cfg_attr(feature="serde-1", serde(with="serde_asref"))]
     pub results: R::Results,
     pub index: usize,
     pub core: R,
@@ -203,7 +204,7 @@ impl<R: BlockRngCore + fmt::Debug> fmt::Debug for BlockRng<R> {
 }
 
 impl<R: BlockRngCore<Item=u32>> RngCore for BlockRng<R>
-where <R as BlockRngCore>::Results: AsRef<[u32]>
+where <R as BlockRngCore>::Results: AsRef<[u32]> + AsMut<[u32]> + Default
 {
     #[inline(always)]
     fn next_u32(&mut self) -> u32 {
@@ -349,7 +350,7 @@ impl<R: BlockRngCore + SeedableRng> SeedableRng for BlockRng<R> {
 /// [`RngCore`]: ../RngCore.t.html
 /// [`BlockRng`]: .BlockRng.s.html
 #[derive(Clone)]
-#[cfg_attr(feature="serde-1", derive(Serialize,Deserialize))]
+//#[cfg_attr(feature="serde-1", derive(Serialize,Deserialize))]
 pub struct BlockRng64<R: BlockRngCore + ?Sized> {
     pub results: R::Results,
     pub index: usize,
@@ -370,7 +371,7 @@ impl<R: BlockRngCore + fmt::Debug> fmt::Debug for BlockRng64<R> {
 }
 
 impl<R: BlockRngCore<Item=u64>> RngCore for BlockRng64<R>
-where <R as BlockRngCore>::Results: AsRef<[u64]>
+where <R as BlockRngCore>::Results: AsRef<[u64]> + AsMut<[u64]> + Default
 {
     #[inline(always)]
     fn next_u32(&mut self) -> u32 {
@@ -501,4 +502,74 @@ impl<R: BlockRngCore + SeedableRng> SeedableRng for BlockRng64<R> {
 
 impl<R: BlockRngCore + CryptoRng> CryptoRng for BlockRng<R> {}
 
+#[cfg(feature="serde-1")]
+mod serde_asref {
+    use serde::{Deserialize, Deserializer, Serialize, Serializer};
+    use serde::de::{Visitor,SeqAccess};
+    use serde::de;
+
+    use core::fmt;
+    use core::convert::AsRef;
+    use BlockRngCore;
+
+    pub fn serialize<R, S, T>(arr: R, ser: S) -> Result<S::Ok, S::Error> 
+    where
+        R: AsRef<[T]>,
+        S: Serializer,
+        T: Serialize,
+    {
+        use serde::ser::SerializeTuple;
+
+        let mut seq = ser.serialize_tuple(arr.as_ref().len())?;
+
+        for e in arr.as_ref().iter() {
+            seq.serialize_element(&e)?;
+        }
+
+        seq.end()
+    }
+
+    #[inline]
+    pub fn deserialize<'de, R, T, D>(de: D) -> Result<[T;RAND_SIZE], D::Error>
+    where
+        R: AsMut<[T]>,
+        T: Deserialize<'de> + Default,
+        D: Deserializer<'de>,
+    {
+        use core::marker::PhantomData;
+        struct ArrayVisitor<T> {
+            _pd: PhantomData<T>,
+        };
+        impl<'de,T> Visitor<'de> for ArrayVisitor<T>
+        where
+            T: Deserialize<'de>+Default+Copy
+        {
+            type Value = [T; RAND_SIZE];
+
+            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                formatter.write_str("Isaac state array")
+            }
+
+            #[inline]
+            fn visit_seq<A>(self, mut seq: A) -> Result<[T; RAND_SIZE], A::Error>
+            where
+                A: SeqAccess<'de>,
+            {
+                let mut out = [Default::default();RAND_SIZE];
+
+                for i in 0..RAND_SIZE {
+                    match seq.next_element()? {
+                        Some(val) => out[i] = val,
+                        None => return Err(de::Error::invalid_length(i, &self)),
+                    };
+                }
+
+                Ok(out)
+            }
+        }
+
+        de.deserialize_tuple(RAND_SIZE, ArrayVisitor{_pd: PhantomData})
+    }
+}
+
 // TODO: implement tests for the above

rand_core/src/lib.rs

@@ -52,6 +52,7 @@ use core::default::Default;
 use core::convert::AsMut;
 
 #[cfg(all(feature="alloc", not(feature="std")))] use alloc::boxed::Box;
+#[cfg(feature="serde-1")] use serde::{Serialize, Deserialize};
 
 pub use error::{ErrorKind, Error};
 
@@ -231,11 +232,14 @@ pub trait RngCore {
 /// [`fill_bytes`]: trait.RngCore.html#tymethod.fill_bytes
 pub trait BlockRngCore {
     /// Results element type, e.g. `u32`.
+    #[cfg(not(feature="serde-1"))]
     type Item;
-    
+    #[cfg(feature="serde-1")]
+    type Item: Serialize;
+
     /// Results type. This is the 'block' an RNG implementing `BlockRngCore`
     /// generates, which will usually be an array like `[u32; 16]`.
-    type Results: AsRef<[Self::Item]> + Default;
+    type Results: AsRef<[Self::Item]> + AsMut<[Self::Item]> + Default;
 
     /// Generate a new block of results.
     fn generate(&mut self, results: &mut Self::Results);