📝 Use doc_auto_cfg

Author: Absolucy

Cargo.toml

@@ -11,10 +11,11 @@ edition = "2021"
 license = "Zlib"
 
 [features]
-default = ["std", "tls", "wyrand", "pcg64", "chacha"]
+default = ["entropy", "std", "tls", "wyrand", "pcg64", "chacha"]
+entropy = []
 alloc = []
 std = ["alloc"]
-tls = ["std", "wyrand"]
+tls = ["entropy", "std", "wyrand"]
 wyrand = []
 pcg64 = []
 chacha = []

src/buffer.rs

@@ -72,7 +72,6 @@ impl<InternalGenerator: Rng<OUTPUT>, const OUTPUT: usize> Rng<OUTPUT>
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<InternalGenerator: Rng<OUTPUT>, const OUTPUT: usize> std::io::Read
 	for BufferedRng<InternalGenerator, OUTPUT>
 {

src/crypto.rs

@@ -1,3 +1,3 @@
-/// Implementation of the ChaCha cryptographic primitives.  
-/// More details can be seen at https://en.wikipedia.org/wiki/Salsa20
+/// Implementation of the ChaCha cryptographic primitives.
+/// More details can be seen at <https://en.wikipedia.org/wiki/Salsa20>
 pub mod chacha;

src/entropy.rs

@@ -1,5 +1,4 @@
 #[cfg(feature = "getrandom_custom")]
-#[cfg_attr(docsrs, doc(cfg(feature = "getrandom_custom")))]
 pub use getrandom::register_custom_getrandom;
 
 #[cfg(all(target_vendor = "apple", not(feature = "getrandom")))]

src/lib.rs

@@ -1,5 +1,5 @@
 #![cfg_attr(not(feature = "std"), no_std)]
-#![cfg_attr(docsrs, feature(doc_cfg))]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #![forbid(missing_docs)]
 #![warn(
 	clippy::perf,
@@ -85,6 +85,7 @@
 //! ## Feature Flags
 //!
 //! * `alloc` (default) - Enables Rust `alloc` lib features, such as a buffering Rng wrapper.
+//! * `entropy` (default) - Allows sourcing entropy from the system. Implied by `getrandom`, too.
 //! * `std` (default) - Enables Rust `std` lib features, such as seeding from OS entropy sources. Requires `alloc` to be enabled.
 //! * `tls` (default) - Enables a thread-local [`WyRand`](rand/wyrand/struct.WyRand.html) RNG (see below). Requires `std` to be enabled.
 //! * `wyrand` (default) - Enable the [`WyRand`](rand/wyrand/struct.WyRand.html) RNG.
@@ -108,18 +109,17 @@ pub use rand::*;
 pub use tls::tls_rng;
 
 #[cfg(feature = "alloc")]
-#[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
 /// Provides a buffered wrapper for RNGs, preventing bits from being wasted.
 pub mod buffer;
 /// Implementation of cryptography, for CSPRNGs.
 pub mod crypto;
 /// Sources for obtaining entropy.
+#[cfg(any(feature = "entropy", feature = "getrandom"))]
 pub mod entropy;
 /// Traits for generating types from an RNG.
 pub mod gen;
 /// RNG algorithms.
 pub mod rand;
 #[cfg(feature = "tls")]
-#[cfg_attr(docsrs, doc(cfg(feature = "tls")))]
 /// Provides a thread-local [`WyRand`] RNG.
 pub mod tls;

src/rand.rs

@@ -11,19 +11,16 @@ use core::ops::RangeBounds;
 /// Implementation of the wyrand PRNG algorithm.
 /// More details can be seen at <https://github.com/wangyi-fudan/wyhash>
 #[cfg(feature = "wyrand")]
-#[cfg_attr(docsrs, doc(cfg(feature = "wyrand")))]
 pub mod wyrand;
 
 /// Implementation of the Pcg64 PRNG algorithm.
 /// More details can be seen at <https://www.pcg-random.org/index.html>
 #[cfg(feature = "pcg64")]
-#[cfg_attr(docsrs, doc(cfg(feature = "pcg64")))]
 pub mod pcg64;
 
 /// Implementation of the ChaCha CSPRNG algorithm.
 /// More details can be seen at <https://en.wikipedia.org/wiki/Salsa20>
 #[cfg(feature = "chacha")]
-#[cfg_attr(docsrs, doc(cfg(feature = "chacha")))]
 pub mod chacha;
 
 /// A trait that represents a random number generator.

src/rand/chacha.rs

@@ -20,13 +20,13 @@ pub type ChaCha20 = ChaCha<20>;
 /// **This generator _is theoretically_ cryptographically secure.**
 #[cfg_attr(feature = "zeroize", derive(Zeroize))]
 #[cfg_attr(feature = "zeroize", zeroize(drop))]
-#[cfg_attr(docsrs, doc(cfg(feature = "chacha")))]
 pub struct ChaCha<const ROUNDS: u8> {
 	state: [u32; 16],
 }
 
 impl<const ROUNDS: u8> ChaCha<ROUNDS> {
 	/// Create a new [`ChaCha`] instance, seeding from the system's default source of entropy.
+	#[cfg(any(feature = "entropy", feature = "getrandom"))]
 	#[must_use]
 	pub fn new() -> Self {
 		let mut key: [u8; 32] = Default::default();
@@ -45,6 +45,7 @@ impl<const ROUNDS: u8> ChaCha<ROUNDS> {
 	}
 }
 
+#[cfg(any(feature = "entropy", feature = "getrandom"))]
 impl<const ROUNDS: u8> Default for ChaCha<ROUNDS> {
 	fn default() -> Self {
 		let mut key: [u8; 32] = Default::default();

src/rand/pcg64.rs

@@ -12,7 +12,6 @@ const PCG_DEFAULT_MULTIPLIER_128: u128 = 47026247687942121848144207491837523525;
 /// **This generator is _NOT_ cryptographically secure.**
 #[cfg_attr(feature = "zeroize", derive(Zeroize))]
 #[cfg_attr(feature = "zeroize", zeroize(drop))]
-#[cfg_attr(docsrs, doc(cfg(feature = "pcg64")))]
 pub struct Pcg64 {
 	seed: u128,
 	state: u128,
@@ -21,7 +20,7 @@ pub struct Pcg64 {
 
 impl Pcg64 {
 	/// Create a new [`Pcg64`] instance, seeding from the system's default source of entropy.
-	#[cfg(feature = "std")]
+	#[cfg(any(feature = "entropy", feature = "getrandom"))]
 	#[must_use]
 	pub fn new() -> Self {
 		let mut entropy: [u8; core::mem::size_of::<u128>()] = Default::default();
@@ -61,7 +60,7 @@ impl Pcg64 {
 	}
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "entropy", feature = "getrandom"))]
 impl Default for Pcg64 {
 	/// Create a new [`Pcg64`] instance, seeding from the system's default source of entropy.
 	fn default() -> Self {

src/rand/wyrand.rs

@@ -10,13 +10,13 @@ use zeroize::Zeroize;
 /// **This generator is _NOT_ cryptographically secure.**
 #[cfg_attr(feature = "zeroize", derive(Zeroize))]
 #[cfg_attr(feature = "zeroize", zeroize(drop))]
-#[cfg_attr(docsrs, doc(cfg(feature = "wyrand")))]
 pub struct WyRand {
 	seed: u64,
 }
 
 impl WyRand {
 	/// Create a new [`WyRand`] instance, seeding from the system's default source of entropy.
+	#[cfg(any(feature = "entropy", feature = "getrandom"))]
 	#[must_use]
 	pub fn new() -> Self {
 		Self::default()
@@ -29,6 +29,7 @@ impl WyRand {
 	}
 }
 
+#[cfg(any(feature = "entropy", feature = "getrandom"))]
 impl Default for WyRand {
 	/// Create a new [`WyRand`] instance, seeding from the system's default source of entropy.
 	fn default() -> Self {

src/tls.rs

@@ -37,7 +37,6 @@ impl SeedableRng<8, 8> for TlsWyRand {
 ///     println!("Random number: {}", rng.generate::<u64>());
 /// });
 /// ```
-#[cfg_attr(docsrs, doc(cfg(feature = "tls")))]
 pub fn tls_rng() -> TlsWyRand {
 	WYRAND.with(|tls| TlsWyRand(tls.clone()))
 }