Fix no_std and alloc builds

rand_core/src/lib.rs

@@ -43,6 +43,7 @@ use core::default::Default;
 use core::convert::AsMut;
 use core::ptr::copy_nonoverlapping;
 
+#[cfg(all(feature="alloc", not(feature="std")))] extern crate alloc;
 #[cfg(all(feature="alloc", not(feature="std")))] use alloc::boxed::Box;
 
 pub use error::Error;

src/distributions/uniform.rs

@@ -119,7 +119,7 @@ use crate::distributions::utils::{WideningMultiply, FloatSIMDUtils, FloatAsSIMD,
 
 #[cfg(not(feature = "std"))]
 #[allow(unused_imports)] // rustc doesn't detect that this is actually used
-use distributions::utils::Float;
+use crate::distributions::utils::Float;
 
 
 #[cfg(feature="simd_support")]

src/distributions/weighted/alias_method.rs

@@ -3,7 +3,9 @@
 
 use super::WeightedError;
 #[cfg(not(feature = "std"))]
-use alloc::vec::Vec;
+use crate::alloc::vec::Vec;
+#[cfg(not(feature = "std"))]
+use crate::alloc::vec;
 use core::fmt;
 use core::iter::Sum;
 use core::ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Sub, SubAssign};

src/distributions/weighted/mod.rs

@@ -14,11 +14,11 @@ pub mod alias_method;
 use crate::Rng;
 use crate::distributions::Distribution;
 use crate::distributions::uniform::{UniformSampler, SampleUniform, SampleBorrow};
-use ::core::cmp::PartialOrd;
+use core::cmp::PartialOrd;
 use core::fmt;
 
 // Note that this whole module is only imported if feature="alloc" is enabled.
-#[cfg(not(feature="std"))] use alloc::vec::Vec;
+#[cfg(not(feature="std"))] use crate::alloc::vec::Vec;
 
 /// A distribution using weighted sampling to pick a discretely selected
 /// item.

src/lib.rs

@@ -53,6 +53,9 @@
 #![cfg_attr(all(feature="alloc", not(feature="std")), feature(alloc))]
 #![cfg_attr(all(feature="simd_support", feature="nightly"), feature(stdsimd))]
 
+#![cfg(all(feature="alloc", not(feature="std")))]
+extern crate alloc;
+
 #[cfg(feature = "getrandom")]
 use getrandom_package as getrandom;
 

src/seq/index.rs

@@ -11,10 +11,10 @@
 #[cfg(feature="alloc")] use core::slice;
 
 #[cfg(feature="std")] use std::vec;
-#[cfg(all(feature="alloc", not(feature="std")))] use alloc::vec::{self, Vec};
+#[cfg(all(feature="alloc", not(feature="std")))] use crate::alloc::vec::{self, Vec};
 // BTreeMap is not as fast in tests, but better than nothing.
 #[cfg(feature="std")] use std::collections::{HashSet};
-#[cfg(all(feature="alloc", not(feature="std")))] use alloc::collections::BTreeSet;
+#[cfg(all(feature="alloc", not(feature="std")))] use crate::alloc::collections::BTreeSet;
 
 #[cfg(feature="alloc")] use crate::distributions::{Distribution, Uniform, uniform::SampleUniform};
 use crate::Rng;
@@ -326,6 +326,7 @@ where R: Rng + ?Sized, IndexVec: From<Vec<X>> {
 
 #[cfg(test)]
 mod test {
+    use crate::alloc::vec;
     use super::*;
 
     #[test]

src/seq/mod.rs

@@ -15,7 +15,7 @@
 
 #[cfg(feature="alloc")] use core::ops::Index;
 
-#[cfg(all(feature="alloc", not(feature="std")))] use alloc::vec::Vec;
+#[cfg(all(feature="alloc", not(feature="std")))] use crate::alloc::vec::Vec;
 
 use crate::Rng;
 #[cfg(feature="alloc")] use crate::distributions::WeightedError;