Update docs

Author: survived

README.md

@@ -30,6 +30,9 @@ Rust versions from 1.66 or higher support a new best-effort optimization
 barrier ([`core::hint::black_box`]).  To use the new optimization barrier,
 enable the `core_hint_black_box` feature.
 
+Rust versions from 1.51 or higher have const generics support. You may enable
+`const-generics` feautre to have `subtle` traits implemented for arrays `[T; N]`.
+
 Versions prior to `2.2` recommended use of the `nightly` feature to enable an
 optimization barrier; this is not required in versions `2.2` and above.
 

src/lib.rs

@@ -41,6 +41,13 @@
 //! inner `u8` by passing it through a volatile read. For more information, see
 //! the _About_ section below.
 //!
+//! Rust versions from 1.66 or higher support a new best-effort optimization
+//! barrier ([`core::hint::black_box`]).  To use the new optimization barrier,
+//! enable the `core_hint_black_box` feature.
+//!
+//! Rust versions from 1.51 or higher have const generics support. You may enable
+//! `const-generics` feautre to have `subtle` traits implemented for arrays `[T; N]`.
+//!
 //! Versions prior to `2.2` recommended use of the `nightly` feature to enable an
 //! optimization barrier; this is not required in versions `2.2` and above.
 //!
@@ -55,18 +62,23 @@
 //!
 //! ## Minimum Supported Rust Version
 //!
-//! Rust **1.51** or higher.
+//! Rust **1.41** or higher.
 //!
 //! Minimum supported Rust version can be changed in the future, but it will be done with a minor version bump.
 //!
 //! ## About
 //!
 //! This library aims to be the Rust equivalent of Go’s `crypto/subtle` module.
 //!
-//! The optimization barrier in `impl From<u8> for Choice` was based on Tim
-//! Maclean's [work on `rust-timing-shield`][rust-timing-shield], which attempts to
-//! provide a more comprehensive approach for preventing software side-channels in
-//! Rust code.
+//! Old versions of the optimization barrier in `impl From<u8> for Choice` were
+//! based on Tim Maclean's [work on `rust-timing-shield`][rust-timing-shield],
+//! which attempts to provide a more comprehensive approach for preventing
+//! software side-channels in Rust code.
+//!
+//! From version `2.2`, it was based on Diane Hosfelt and Amber Sprenkels' work on
+//! "Secret Types in Rust".  Version `2.3` adds the `core_hint_black_box` feature,
+//! which uses the original method through the [`core::hint::black_box`] function
+//! from the Rust standard library.
 //!
 //! `subtle` is authored by isis agora lovecruft and Henry de Valence.
 //!
@@ -81,6 +93,7 @@
 //! **USE AT YOUR OWN RISK**
 //!
 //! [docs]: https://docs.rs/subtle
+//! [`core::hint::black_box`]: https://doc.rust-lang.org/core/hint/fn.black_box.html
 //! [rust-timing-shield]: https://www.chosenplaintext.ca/open-source/rust-timing-shield/security
 
 #[cfg(feature = "std")]
@@ -856,7 +869,7 @@ macro_rules! generate_unsigned_integer_greater {
                 Choice::from((bit & 1) as u8)
             }
         }
-    }
+    };
 }
 
 generate_unsigned_integer_greater!(u8, 8);