Add an implementation of alias method for weighted indices

benches/distributions.rs

@@ -187,6 +187,11 @@ distr_int!(distr_weighted_u32, usize, WeightedIndex::new(&[1u32, 2, 3, 4, 12, 0,
 distr_int!(distr_weighted_f64, usize, WeightedIndex::new(&[1.0f64, 0.001, 1.0/3.0, 4.01, 0.0, 3.3, 22.0, 0.001]).unwrap());
 distr_int!(distr_weighted_large_set, usize, WeightedIndex::new((0..10000).rev().chain(1..10001)).unwrap());
 
+distr_int!(distr_weighted_alias_method_i8, usize, weighted::alias_method::WeightedIndex::new(vec![1i8, 2, 3, 4, 12, 0, 2, 1]).unwrap());
+distr_int!(distr_weighted_alias_method_u32, usize, weighted::alias_method::WeightedIndex::new(vec![1u32, 2, 3, 4, 12, 0, 2, 1]).unwrap());
+distr_int!(distr_weighted_alias_method_f64, usize, weighted::alias_method::WeightedIndex::new(vec![1.0f64, 0.001, 1.0/3.0, 4.01, 0.0, 3.3, 22.0, 0.001]).unwrap());
+distr_int!(distr_weighted_alias_method_large_set, usize, weighted::alias_method::WeightedIndex::new((0..10000).rev().chain(1..10001).collect()).unwrap());
+
 // construct and sample from a range
 macro_rules! gen_range_int {
     ($fnn:ident, $ty:ident, $low:expr, $high:expr) => {

src/distributions/mod.rs

@@ -198,7 +198,7 @@ pub use self::bernoulli::Bernoulli;
 
 pub mod uniform;
 mod bernoulli;
-#[cfg(feature="alloc")] mod weighted;
+#[cfg(feature="alloc")] pub mod weighted;
 #[cfg(feature="std")] mod unit_sphere;
 #[cfg(feature="std")] mod unit_circle;
 #[cfg(feature="std")] mod gamma;