remove specialization and have a non-simd fallback for stable

Cargo.toml

@@ -18,8 +18,11 @@ edition = "2018"
 azure-devops = { project = "alecmocatta/streaming_algorithms", pipeline = "tests", build = "16" }
 maintenance = { status = "actively-developed" }
 
+[features]
+nightly = ["packed_simd"]
+
 [dependencies]
 twox-hash = "1.1"
 serde = { version = "1.0", features = ["derive"] }
 rand = { version = "0.7", features = ["small_rng"] }
-packed_simd = { version = "0.3", features = ["into_bits"] }
+packed_simd = { version = "0.3", features = ["into_bits"], optional = true }

src/count_min.rs

@@ -20,14 +20,15 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
-use super::f64_to_usize;
-use crate::traits::{Intersect, IntersectPlusUnionIsPlus, New, UnionAssign};
 use serde::{Deserialize, Serialize};
 use std::{
 	borrow::Borrow, cmp::max, convert::TryFrom, fmt, hash::{Hash, Hasher}, marker::PhantomData, ops
 };
 use twox_hash::XxHash;
 
+use super::f64_to_usize;
+use crate::traits::{Intersect, IntersectPlusUnionIsPlus, New, UnionAssign};
+
 /// An implementation of a [count-min sketch](https://en.wikipedia.org/wiki/Count–min_sketch) data structure with *conservative updating* for increased accuracy.
 ///
 /// This data structure is also known as a [counting Bloom filter](https://en.wikipedia.org/wiki/Bloom_filter#Counting_filters).
@@ -75,7 +76,7 @@ where
 	where
 		Q: Hash,
 		K: Borrow<Q>,
-		C: for<'a> ops::AddAssign<&'a V>,
+		C: for<'a> ops::AddAssign<&'a V> + IntersectPlusUnionIsPlus,
 	{
 		if !<C as IntersectPlusUnionIsPlus>::VAL {
 			let offsets = self.offsets(key);