Update the README and Rustdoc about MSRV

README.md

@@ -310,21 +310,27 @@ available on crates.io, such as the [aHash][ahash-crate] crate.
 [ahash-crate]: https://crates.io/crates/ahash
 
 
-## Minimum Supported Rust Version
+## Minimum Supported Rust Versions
 
-This crate's minimum supported Rust version (MSRV) is 1.45.2.
+This crate's minimum supported Rust versions (MSRV) are the followings:
 
-<!--
-- quanta requires 1.45.
-- aHash 0.5 requires 1.43.
-- cht requires 1.41.
--->
+| Enabled Feature      | MSRV        |
+|:---------------------|:------------|
+| no feature (default) | Rust 1.45.2 |
+| `future`             | Rust 1.46.0 |
 
 If no feature is enabled, MSRV will be updated conservatively. When using other
 features, like `future`, MSRV might be updated more frequently, up to the latest
 stable. In both cases, increasing MSRV is _not_ considered a semver-breaking
 change.
 
+<!--
+- socket2 0.4.0 requires 1.46.
+- quanta requires 1.45.
+- aHash 0.5 requires 1.43.
+- cht requires 1.41.
+-->
+
 
 ## Road Map
 

src/lib.rs

@@ -53,9 +53,14 @@
 //! [sync-seg-cache-struct]: ./sync/struct.SegmentedCache.html
 //! [unsync-cache-struct]: ./unsync/struct.Cache.html
 //!
-//! # Minimum Supported Rust Version
+//! # Minimum Supported Rust Versions
 //!
-//! This crate's minimum supported Rust version (MSRV) is 1.45.2.
+//! This crate's minimum supported Rust versions (MSRV) are the followings:
+//!
+//! | Enabled Feature      | MSRV        |
+//! |:---------------------|:------------|
+//! | no feature (default) | Rust 1.45.2 |
+//! | `future`             | Rust 1.46.0 |
 //!
 //! If no crate feature is enabled, MSRV will be updated conservatively. When using
 //! features like `future`, MSRV might be updated more frequently, up to the latest