Use explicit features rather than implicit.

CHANGELOG.md

@@ -20,6 +20,7 @@ You may also find the [Upgrade Guide](https://rust-random.github.io/book/update.
 - Fix portability of `rand::distributions::Slice` (#1469)
 - Rename `rand::distributions` to `rand::distr` (#1470)
 - The `serde1` feature has been renamed `serde` (#1477)
+- The implicit feature `rand_chacha` has been removed. This is enabled by `std_rng`. (#1473)
 - Mark `WeightError`, `PoissonError`, `BinomialError` as `#[non_exhaustive]` (#1480).
 - Add `UniformUsize` and use to make `Uniform` for `usize` portable (#1487)
 - Remove support for generating `isize` and `usize` values with `Standard`, `Uniform` and `Fill` and usage as a `WeightedAliasIndex` weight (#1487)

Cargo.toml

@@ -46,7 +46,7 @@ getrandom = ["rand_core/getrandom"]
 simd_support = ["zerocopy/simd-nightly"]
 
 # Option (enabled by default): enable StdRng
-std_rng = ["rand_chacha"]
+std_rng = ["dep:rand_chacha"]
 
 # Option: enable SmallRng
 small_rng = []
@@ -56,6 +56,9 @@ small_rng = []
 # Note: enabling this option is expected to affect reproducibility of results.
 unbiased = []
 
+# Option: enable logging
+log = ["dep:log"]
+
 [workspace]
 members = [
     "rand_core",

rand_core/Cargo.toml

@@ -27,6 +27,7 @@ all-features = true
 [features]
 std = ["alloc", "getrandom?/std"]
 alloc = []  # enables Vec and Box support without std
+getrandom = ["dep:getrandom"]
 serde = ["dep:serde"] # enables serde for BlockRng wrapper
 
 [dependencies]

rand_distr/Cargo.toml

@@ -29,7 +29,7 @@ alloc = ["rand/alloc"]
 # feature (default-enabled) will have the same effect.
 std_math = ["num-traits/std"]
 
-serde = ["dep:serde", "rand/serde"]
+serde = ["dep:serde", "dep:serde_with", "rand/serde"]
 
 [dependencies]
 rand = { path = "..", version = "=0.9.0-alpha.1", default-features = false }

rand_distr/src/dirichlet.rs

@@ -14,13 +14,13 @@ use crate::{Beta, Distribution, Exp1, Gamma, Open01, StandardNormal};
 use core::fmt;
 use num_traits::{Float, NumCast};
 use rand::Rng;
-#[cfg(feature = "serde_with")]
+#[cfg(feature = "serde")]
 use serde_with::serde_as;
 
 use alloc::{boxed::Box, vec, vec::Vec};
 
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "serde_with", serde_as)]
+#[cfg_attr(feature = "serde", serde_as)]
 struct DirichletFromGamma<F, const N: usize>
 where
     F: Float,
@@ -171,7 +171,7 @@ where
 }
 
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "serde_with", serde_as)]
+#[cfg_attr(feature = "serde", serde_as)]
 enum DirichletRepr<F, const N: usize>
 where
     F: Float,
@@ -214,7 +214,7 @@ where
 /// let samples = dirichlet.sample(&mut rand::rng());
 /// println!("{:?} is from a Dirichlet([1.0, 2.0, 3.0]) distribution", samples);
 /// ```
-#[cfg_attr(feature = "serde_with", serde_as)]
+#[cfg_attr(feature = "serde", serde_as)]
 #[derive(Clone, Debug, PartialEq)]
 pub struct Dirichlet<F, const N: usize>
 where