Remove rkyv support

Support will instead be directly provided by the `rkyv` crate via an
optional feature.

Author: Amanieu

Cargo.toml

@@ -19,9 +19,6 @@ ahash = { version = "0.8.7", default-features = false, optional = true }
 # For external trait impls
 rayon = { version = "1.0", optional = true }
 serde = { version = "1.0.25", default-features = false, optional = true }
-rkyv = { version = "0.7.42", optional = true, default-features = false, features = [
-    "alloc",
-] }
 borsh = { version = "1.5.0", default-features = false, optional = true, features = ["derive"]}
 
 # When built as part of libstd
@@ -45,7 +42,6 @@ fnv = "1.0.7"
 serde_test = "1.0"
 doc-comment = "0.3.1"
 bumpalo = { version = "3.13.0", features = ["allocator-api2"] }
-rkyv = { version = "0.7.42", features = ["validation"] }
 
 [features]
 default = ["default-hasher", "inline-more", "allocator-api2", "equivalent", "raw-entry"]

README.md

@@ -102,7 +102,6 @@ This crate has the following Cargo features:
 - `nightly`: Enables nightly-only features including: `#[may_dangle]`.
 - `serde`: Enables serde serialization support.
 - `borsh`: Enables borsh serialization support.
-- `rkyv`: Enables rkyv serialization support.
 - `rayon`: Enables rayon parallel iterator support.
 - `equivalent`: Allows comparisons to be customized with the `Equivalent` trait.
 - `raw-entry`: Enables access to the deprecated `RawEntry` API.

src/external_trait_impls/mod.rs

@@ -2,7 +2,5 @@
 mod borsh;
 #[cfg(feature = "rayon")]
 pub(crate) mod rayon;
-#[cfg(feature = "rkyv")]
-mod rkyv;
 #[cfg(feature = "serde")]
 mod serde;