corrected some rustdocs in rng.rs; also trying to pass checks

chacha20/src/backends/avx2.rs

@@ -1,6 +1,9 @@
-use crate::{Rounds, ChaChaCore, Variant};
+use crate::Rounds;
 use core::marker::PhantomData;
 
+#[cfg(feature = "rand_core")]
+use crate::{ChaChaCore, Variant};
+
 #[cfg(feature = "cipher")]
 use crate::{
     STATE_WORDS,
@@ -61,6 +64,7 @@ where
 
 #[inline]
 #[target_feature(enable = "avx2")]
+#[cfg(feature = "rand_core")]
 pub(crate) unsafe fn rng_inner<R, V>(core: &mut ChaChaCore<R, V>, buffer: &mut [u32; 64])
 where
     R: Rounds,
@@ -85,7 +89,7 @@ where
         _pd: PhantomData,
     };
 
-    backend.gen_par_ks_blocks(buffer);
+    backend.rng_gen_par_ks_blocks(buffer);
 
     core.state[12] = _mm256_extract_epi32(backend.ctr[0], 0) as u32;
 }
@@ -151,7 +155,7 @@ impl<R: Rounds> StreamBackend for Backend<R> {
 #[cfg(feature = "rand_core")]
 impl<R: Rounds> Backend<R> {
     #[inline(always)]
-    fn gen_par_ks_blocks(&mut self, blocks: &mut [u32; 64]) {
+    fn rng_gen_par_ks_blocks(&mut self, blocks: &mut [u32; 64]) {
         unsafe {
             let vs = rounds::<R>(&self.v, &self.ctr);
 

chacha20/src/backends/sse2.rs

@@ -1,4 +1,7 @@
-use crate::{ChaChaCore, Rounds, Variant};
+use crate::Rounds;
+
+#[cfg(feature = "rand_core")]
+use crate::{ChaChaCore, Variant};
 
 #[cfg(feature = "cipher")]
 use crate::{STATE_WORDS, chacha::Block};

chacha20/src/rng.rs

@@ -143,7 +143,7 @@ macro_rules! impl_chacha_rng {
         /// rounds is the minimum potentially secure configuration, and 20 rounds is widely used as a
         /// conservative choice.
         ///
-        /// We use a 32-bit counter and 32-bit stream identifier as in the IETF implementation[^3]
+        /// We use a 32-bit counter and 96-bit stream identifier as in the IETF implementation[^3]
         /// except that we use a stream identifier in place of a nonce. A 32-bit counter over 64-byte
         /// (16 word) blocks allows 256 GiB of output before cycling, and the stream identifier allows
         /// 2<sup>96</sup> unique streams of output per seed. Both counter and stream are initialized
@@ -157,35 +157,40 @@ macro_rules! impl_chacha_rng {
         /// seed      seed      seed      seed
         /// counter   stream_id stream_id stream_id
         /// ```
-        /// This implementation uses an output buffer of sixteen `u32` words, and uses
-        /// [`BlockRng`] to implement the [`RngCore`] methods.
+        /// This implementation uses an output buffer of 64 `u32` words.
         /// # Example for `ChaCha20Rng`
         ///
         /// ```rust
         /// use chacha20::ChaCha20Rng;
         /// // use rand_core traits
         /// use rand_core::{SeedableRng, RngCore};
         ///
-        /// // the following inputs are examples and are neither recommended nor suggested values
+        /// // the following inputs are examples and are neither 
+        /// // recommended nor suggested values
         ///
         /// let seed = [42u8; 32];
         /// let mut rng = ChaCha20Rng::from_seed(seed);
         /// rng.set_stream(100);
         ///
-        /// // you can also use a [u8; 12] in `.set_stream()`, which has a *minor*
-        /// // performance benefit over a u128
+        /// // you can also use a [u8; 12] in `.set_stream()`, which has a 
+        /// // *minor* performance benefit over a u128
         /// rng.set_stream([3u8; 12]);
         ///
         ///
         /// rng.set_word_pos(5);
         ///
-        /// // you can also use a [u8; 5] in `.set_word_pos()`, which has a *minor*
-        /// // performance benefit over a u64
+        /// // you can also use a [u8; 5] in `.set_word_pos()`, which has a 
+        /// // *minor* performance benefit over a u64
         /// rng.set_word_pos([2u8; 5]);
         ///
         /// let x = rng.next_u32();
         /// let mut array = [0u8; 32];
         /// rng.fill_bytes(&mut array);
+        /// 
+        /// // in case you need to zeroize the RNG's buffer, ensure that 
+        /// // the "zeroize" feature is enabled in Cargo.toml and run
+        /// # #[cfg(feature = "zeroize")]
+        /// rng.zeroize();
         /// ```
         ///
         /// The other Rngs from this crate are initialized similarly.