From 335c39078726cb38e51adf16012fb0366e167ef9 Mon Sep 17 00:00:00 2001
From: Paul Dicker <pitdicker@gmail.com>
Date: Tue, 8 May 2018 13:56:16 +0200
Subject: [PATCH 1/2] Implement From<Error> for io::Error

---
 rand_core/src/error.rs | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/rand_core/src/error.rs b/rand_core/src/error.rs
index 34cfbf8c8e4..594d3576986 100644
--- a/rand_core/src/error.rs
+++ b/rand_core/src/error.rs
@@ -14,6 +14,8 @@ use core::fmt;
 
 #[cfg(feature="std")]
 use std::error::Error as stdError;
+#[cfg(feature="std")]
+use std::io;
 
 /// Error kind which can be matched over.
 #[derive(PartialEq, Eq, Debug, Copy, Clone)]
@@ -161,3 +163,17 @@ impl stdError for Error {
         self.cause.as_ref().map(|e| e.as_ref() as &stdError)
     }
 }
+
+#[cfg(feature="std")]
+impl From<Error> for io::Error {
+    fn from(error: Error) -> Self {
+        use std::io::ErrorKind::*;
+        match error.kind {
+            ErrorKind::Unavailable => io::Error::new(NotFound, error),
+            ErrorKind::Unexpected |
+            ErrorKind::Transient => io::Error::new(Other, error),
+            ErrorKind::NotReady => io::Error::new(WouldBlock, error),
+            ErrorKind::__Nonexhaustive => unreachable!(),
+        }
+    }
+}

From 7959fbf63f6f66f83758fc94bd44b98c9295d645 Mon Sep 17 00:00:00 2001
From: Paul Dicker <pitdicker@gmail.com>
Date: Tue, 8 May 2018 13:56:30 +0200
Subject: [PATCH 2/2] Implement std::io::Read for RngCore

---
 rand_core/src/lib.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/rand_core/src/lib.rs b/rand_core/src/lib.rs
index fc8c419eeb3..2f87fd2b2e4 100644
--- a/rand_core/src/lib.rs
+++ b/rand_core/src/lib.rs
@@ -439,3 +439,11 @@ impl<R: RngCore + ?Sized> RngCore for Box<R> {
         (**self).try_fill_bytes(dest)
     }
 }
+
+#[cfg(feature="std")]
+impl std::io::Read for RngCore {
+    fn read(&mut self, buf: &mut [u8]) -> Result<usize, std::io::Error> {
+        self.try_fill_bytes(buf)?;
+        Ok(buf.len())
+    }
+}