Auto merge of #22541 - Manishearth:rollup, r=Gankro 1.0.0-alpha.2

Continued from #22520

3 files changed, 14 insertions, 5 deletions

diff --git a/src/librand/distributions/mod.rs b/src/librand/distributions/mod.rs
index d1d24cea871..5a85552dc38 100644
--- a/src/librand/distributions/mod.rs
+++ b/src/librand/distributions/mod.rs
@@ -21,6 +21,7 @@
 
 use core::prelude::*;
 use core::num::{Float, Int};
+use core::marker::PhantomData;
 
 use {Rng, Rand};
 
@@ -56,7 +57,13 @@ pub trait IndependentSample<Support>: Sample<Support> {
 
 /// A wrapper for generating types that implement `Rand` via the
 /// `Sample` & `IndependentSample` traits.
-pub struct RandSample<Sup>;
+pub struct RandSample<Sup> { _marker: PhantomData<Sup> }
+
+impl<Sup> RandSample<Sup> {
+    pub fn new() -> RandSample<Sup> {
+        RandSample { _marker: PhantomData }
+    }
+}
 
 impl<Sup: Rand> Sample<Sup> for RandSample<Sup> {
     fn sample<R: Rng>(&mut self, rng: &mut R) -> Sup { self.ind_sample(rng) }
@@ -285,7 +292,7 @@ mod tests {
 
     #[test]
     fn test_rand_sample() {
-        let mut rand_sample = RandSample::<ConstRand>;
+        let mut rand_sample = RandSample::<ConstRand>::new();
 
         assert_eq!(rand_sample.sample(&mut ::test::rng()), ConstRand(0));
         assert_eq!(rand_sample.ind_sample(&mut ::test::rng()), ConstRand(0));
diff --git a/src/librand/isaac.rs b/src/librand/isaac.rs
index f15523fc010..701749ff344 100644
--- a/src/librand/isaac.rs
+++ b/src/librand/isaac.rs
@@ -215,7 +215,7 @@ impl<'a> SeedableRng<&'a [u32]> for IsaacRng {
     fn reseed(&mut self, seed: &'a [u32]) {
         // make the seed into [seed[0], seed[1], ..., seed[seed.len()
         // - 1], 0, 0, ...], to fill rng.rsl.
-        let seed_iter = seed.iter().map(|&x| x).chain(repeat(0u32));
+        let seed_iter = seed.iter().cloned().chain(repeat(0u32));
 
         for (rsl_elem, seed_elem) in self.rsl.iter_mut().zip(seed_iter) {
             *rsl_elem = seed_elem;
@@ -458,7 +458,7 @@ impl<'a> SeedableRng<&'a [u64]> for Isaac64Rng {
     fn reseed(&mut self, seed: &'a [u64]) {
         // make the seed into [seed[0], seed[1], ..., seed[seed.len()
         // - 1], 0, 0, ...], to fill rng.rsl.
-        let seed_iter = seed.iter().map(|&x| x).chain(repeat(0u64));
+        let seed_iter = seed.iter().cloned().chain(repeat(0u64));
 
         for (rsl_elem, seed_elem) in self.rsl.iter_mut().zip(seed_iter) {
             *rsl_elem = seed_elem;
diff --git a/src/librand/lib.rs b/src/librand/lib.rs
index 915c70bbf8c..7588bf7c515 100644
--- a/src/librand/lib.rs
+++ b/src/librand/lib.rs
@@ -41,6 +41,7 @@ extern crate core;
 #[cfg(test)] #[macro_use] extern crate log;
 
 use core::prelude::*;
+use core::marker::PhantomData;
 
 pub use isaac::{IsaacRng, Isaac64Rng};
 pub use chacha::ChaChaRng;
@@ -206,7 +207,7 @@ pub trait Rng : Sized {
     ///                     .collect::<Vec<(f64, bool)>>());
     /// ```
     fn gen_iter<'a, T: Rand>(&'a mut self) -> Generator<'a, T, Self> {
-        Generator { rng: self }
+        Generator { rng: self, _marker: PhantomData }
     }
 
     /// Generate a random value in the range [`low`, `high`).
@@ -317,6 +318,7 @@ pub trait Rng : Sized {
 /// This iterator is created via the `gen_iter` method on `Rng`.
 pub struct Generator<'a, T, R:'a> {
     rng: &'a mut R,
+    _marker: PhantomData<T>
 }
 
 impl<'a, T: Rand, R: Rng> Iterator for Generator<'a, T, R> {