Lower Rustc version requirement to 1.9 for rand_core

Author: pitdicker

.travis.yml

@@ -14,6 +14,11 @@ matrix:
         - cargo test --tests --no-default-features
         - cargo test --package rand_core --no-default-features
         - cargo test --features serde1,log
+    - rust: 1.9.0
+      install:
+      script:
+        # Ensure minimum rustc version for rand_core.
+        - cargo test --package rand_core --lib
     - rust: stable
       os: osx
       install:

rand_core/README.md

@@ -4,7 +4,7 @@
 [![Build Status](https://ci.appveyor.com/api/projects/status/github/rust-lang-nursery/rand?svg=true)](https://ci.appveyor.com/project/alexcrichton/rand)
 [![Latest version](https://img.shields.io/crates/v/rand_core.svg)](https://crates.io/crates/rand_core)
 [![Documentation](https://docs.rs/rand_core/badge.svg)](https://docs.rs/rand_core)
-[![Minimum rustc version](https://img.shields.io/badge/rustc-1.22+-yellow.svg)](https://github.com/rust-lang-nursery/rand#rust-version-requirements)
+[![Minimum rustc version](https://img.shields.io/badge/rustc-1.9+-yellow.svg)](https://github.com/rust-lang-nursery/rand#rust-version-requirements)
 
 Core traits and error types of the [rand] library, plus tools for implementing
 RNGs.
@@ -53,6 +53,16 @@ default features will also enable `std` support in `rand_core`.
 The `serde1` feature can be used to derive `Serialize` and `Deserialize` for RNG
 implementations that use the `BlockRng` or `BlockRng64` wrappers.
 
+### Rust version requirements
+
+`rand_core` works with a wide range of Rustc versions, with the oldest supported
+version being **Rustc 1.9.0**. The optional `serde1` feature requires a higher
+Rustc version, as it depends on the minimum version supported by Serde.
+
+Travis CI always has a build with a pinned version of Rustc matching the oldest
+supported Rust release. The current policy is that this can be updated in any
+`rand_core` release if required, but the change must be noted in the changelog.
+
 
 # License
 

rand_core/src/error.rs

@@ -97,13 +97,14 @@ pub struct Error {
 
 impl Error {
     /// Create a new instance, with specified kind and a message.
+    #[cfg(feature="std")]
     pub fn new(kind: ErrorKind, msg: &'static str) -> Self {
-        #[cfg(feature="std")] {
-            Error { kind, msg, cause: None }
-        }
-        #[cfg(not(feature="std"))] {
-            Error { kind, msg }
-        }
+        Error { kind: kind, msg: msg, cause: None }
+    }
+    /// Create a new instance, with specified kind and a message.
+    #[cfg(not(feature="std"))]
+    pub fn new(kind: ErrorKind, msg: &'static str) -> Self {
+        Error { kind: kind, msg: msg, cause: None }
     }
 
     /// Create a new instance, with specified kind, message, and a
@@ -119,7 +120,7 @@ impl Error {
     pub fn with_cause<E>(kind: ErrorKind, msg: &'static str, cause: E) -> Self
         where E: Into<Box<stdError + Send + Sync>>
     {
-        Error { kind, msg, cause: Some(cause.into()) }
+        Error { kind: kind, msg: msg, cause: Some(cause.into()) }
     }
 
     /// Create a new instance, with specified kind, message, and a
@@ -128,7 +129,7 @@ impl Error {
     /// In `no_std` mode the *cause* is ignored.
     #[cfg(not(feature="std"))]
     pub fn with_cause<E>(kind: ErrorKind, msg: &'static str, _cause: E) -> Self {
-        Error { kind, msg }
+        Error { kind: kind, msg: msg }
     }
 
     /// Take the cause, if any. This allows the embedded cause to be extracted.
@@ -139,18 +140,24 @@ impl Error {
     }
 }
 
+#[cfg(feature="std")]
 impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        #[cfg(feature="std")] {
-            if let Some(ref cause) = self.cause {
-                return write!(f, "{} ({}); cause: {}",
-                        self.msg, self.kind.description(), cause);
-            }
+        if let Some(ref cause) = self.cause {
+            return write!(f, "{} ({}); cause: {}",
+                    self.msg, self.kind.description(), cause);
         }
         write!(f, "{} ({})", self.msg, self.kind.description())
     }
 }
 
+#[cfg(not(feature="std"))]
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{} ({})", self.msg, self.kind.description())
+    }
+}
+
 #[cfg(feature="std")]
 impl stdError for Error {
     fn description(&self) -> &str {

rand_core/src/impls.rs

@@ -212,7 +212,7 @@ impl<R: BlockRngCore> BlockRng<R> {
     pub fn new(core: R) -> BlockRng<R>{
         let results_empty = R::Results::default();
         BlockRng {
-            core,
+            core: core,
             index: results_empty.as_ref().len(),
             results: results_empty,
         }
@@ -355,7 +355,7 @@ impl<R: BlockRngCore + SeedableRng> SeedableRng for BlockRng<R> {
     }
 
     fn from_rng<S: RngCore>(rng: S) -> Result<Self, Error> {
-        Ok(Self::new(R::from_rng(rng)?))
+        Ok(Self::new(try!(R::from_rng(rng))))
     }
 }
 
@@ -400,7 +400,7 @@ impl<R: BlockRngCore> BlockRng64<R> {
     pub fn new(core: R) -> BlockRng64<R>{
         let results_empty = R::Results::default();
         BlockRng64 {
-            core,
+            core: core,
             index: results_empty.as_ref().len(),
             half_used: false,
             results: results_empty,
@@ -534,7 +534,7 @@ impl<R: BlockRngCore + SeedableRng> SeedableRng for BlockRng64<R> {
     }
 
     fn from_rng<S: RngCore>(rng: S) -> Result<Self, Error> {
-        Ok(Self::new(R::from_rng(rng)?))
+        Ok(Self::new(try!(R::from_rng(rng))))
     }
 }
 

rand_core/src/lib.rs

@@ -381,7 +381,7 @@ pub trait SeedableRng: Sized {
     /// [`OsRng`]: ../rand/os/struct.OsRng.html
     fn from_rng<R: RngCore>(mut rng: R) -> Result<Self, Error> {
         let mut seed = Self::Seed::default();
-        rng.try_fill_bytes(seed.as_mut())?;
+        try!(rng.try_fill_bytes(seed.as_mut()));
         Ok(Self::from_seed(seed))
     }
 }