Add serde to rand_core::impl::{BlockRng, BlockRng64}

Author: pitdicker

Cargo.toml

@@ -23,7 +23,7 @@ nightly = ["i128_support"] # enables all features requiring nightly rust
 std = ["rand_core/std", "alloc", "libc", "winapi", "cloudabi", "fuchsia-zircon"]
 alloc = ["rand_core/alloc"]  # enables Vec and Box support (without std)
 i128_support = [] # enables i128 and u128 support
-serde-1 = ["serde", "serde_derive"] # enables serialisation for PRNGs
+serde-1 = ["serde", "serde_derive", "rand_core/serde-1"] # enables serialization for PRNGs
 
 [workspace]
 members = ["rand_core"]

rand_core/Cargo.toml

@@ -22,3 +22,8 @@ appveyor = { repository = "alexcrichton/rand" }
 # default = ["std"]
 std = ["alloc"]    # use std library; should be default but for above bug
 alloc = []  # enables Vec and Box support without std
+serde-1 = ["serde", "serde_derive"] # enables serde for BlockRng wrapper
+
+[dependencies]
+serde = { version = "1", optional = true }
+serde_derive = { version = "1", optional = true }

rand_core/src/impls.rs

@@ -27,6 +27,8 @@ use core::cmp::min;
 use core::mem::size_of;
 use {RngCore, BlockRngCore, CryptoRng, SeedableRng, Error};
 
+#[cfg(feature="serde-1")] use serde::{Serialize, Deserialize};
+
 /// Implement `next_u64` via `next_u32`, little-endian order.
 pub fn next_u64_via_u32<R: RngCore + ?Sized>(rng: &mut R) -> u64 {
     // Use LE; we explicitly generate one value before the next.
@@ -184,7 +186,11 @@ 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))]
 pub struct BlockRng<R: BlockRngCore + ?Sized> {
+    #[cfg_attr(feature="serde-1", serde(bound(
+        serialize = "R::Results: Serialize",
+        deserialize = "R::Results: Deserialize<'de>")))]
     pub results: R::Results,
     pub index: usize,
     pub core: R,
@@ -347,7 +353,11 @@ impl<R: BlockRngCore + SeedableRng> SeedableRng for BlockRng<R> {
 /// [`RngCore`]: ../RngCore.t.html
 /// [`BlockRng`]: struct.BlockRng.html
 #[derive(Clone)]
+#[cfg_attr(feature="serde-1", derive(Serialize, Deserialize))]
 pub struct BlockRng64<R: BlockRngCore + ?Sized> {
+    #[cfg_attr(feature="serde-1", serde(bound(
+        serialize = "R::Results: Serialize",
+        deserialize = "R::Results: Deserialize<'de>")))]
     pub results: R::Results,
     pub index: usize,
     pub half_used: bool, // true if only half of the previous result is used

rand_core/src/lib.rs

@@ -44,6 +44,8 @@
 
 #[cfg(feature="std")] extern crate core;
 #[cfg(all(feature = "alloc", not(feature="std")))] extern crate alloc;
+#[cfg(feature="serde-1")] extern crate serde;
+#[cfg(feature="serde-1")] #[macro_use] extern crate serde_derive;
 
 
 use core::default::Default;