Remove once_cell dependency (#440)

Author: FalkWoldmann

Cargo.toml

@@ -18,7 +18,6 @@ value-trait = { version = "0.12" }
 beef = { version = "0.5", optional = true }
 halfbrown = "0.4"
 # ahash known key
-once_cell = { version = "1.21", optional = true }
 ahash = { version = "0.8", optional = true }
 
 # serde compatibilty
@@ -73,7 +72,7 @@ value-no-dup-keys = []
 # used for enabeling known keys in favour of a slower
 # hasher that is not protected against hash collision
 # attacks
-known-key = ["once_cell", "ahash"]
+known-key = ["ahash"]
 
 # use 8 number at once parsing strategy
 swar-number-parsing = []

src/known_key.rs

@@ -2,12 +2,11 @@ use crate::BorrowedValue as Value;
 use crate::cow::Cow;
 use crate::prelude::*;
 use halfbrown::RawEntryMut;
-use std::fmt;
 use std::hash::BuildHasher;
+use std::{fmt, sync::OnceLock};
 
 use ahash::{AHasher, RandomState};
-use once_cell::sync::OnceCell;
-static NOT_RANDOM: OnceCell<RandomState> = OnceCell::new();
+static NOT_RANDOM: OnceLock<RandomState> = OnceLock::new();
 
 /// `AHash` `BuildHasher` that uses a startup initialized random state for known keys
 #[derive(Clone)]