Rework specialization (#384)

* Rework specialization

* Add functions operating solely on `Copy` types

Author: TDecking

benches/bench.rs

@@ -80,7 +80,7 @@ impl<T: Copy> Vector<T> for SmallVec<T, VEC_SIZE> {
     }
 
     fn from_elems(val: &[T]) -> Self {
-        SmallVec::from_slice(val)
+        SmallVec::from(val)
     }
 
     fn extend_from_slice(&mut self, other: &[T]) {
@@ -278,17 +278,6 @@ fn gen_from_elem<V: Vector<u64>>(n: usize, b: &mut Bencher) {
     });
 }
 
-#[bench]
-fn bench_insert_from_slice(b: &mut Bencher) {
-    let v: Vec<u64> = (0..SPILLED_SIZE as _).collect();
-    b.iter(|| {
-        let mut vec = SmallVec::<u64, VEC_SIZE>::new();
-        vec.insert_from_slice(0, &v);
-        vec.insert_from_slice(0, &v);
-        vec
-    });
-}
-
 #[bench]
 fn bench_macro_from_list(b: &mut Bencher) {
     b.iter(|| {

fuzz/fuzz_targets/smallvec_ops.rs

@@ -139,7 +139,7 @@ fn do_test<const N: usize>(data: &[u8]) -> SmallVec<u8, N> {
                 }
             }
             22 => {
-                v = SmallVec::from_slice(data);
+                v = SmallVec::from(data);
             }
 
             23 => {
@@ -149,10 +149,10 @@ fn do_test<const N: usize>(data: &[u8]) -> SmallVec<u8, N> {
             }
 
             24 => {
-                if v.len() < CAP_GROWTH {
-                    let insert_pos = next_usize!(bytes) % (v.len() + 1);
-                    v.insert_from_slice(insert_pos, data);
-                }
+                let a = next_usize!(bytes) % (v.len() + 1);
+                let b = next_usize!(bytes) % (v.len() + 1);
+                let (start, end) = (a.min(b), a.max(b));
+                v.extend_from_within(start..end);
             }
 
             25 => {
@@ -161,7 +161,7 @@ fn do_test<const N: usize>(data: &[u8]) -> SmallVec<u8, N> {
                 }
             }
             26 => {
-                v = SmallVec::from_elem(next_u8!(bytes), next_usize!(bytes));
+                v = smallvec::from_elem(next_u8!(bytes), next_usize!(bytes));
             }
             _ => panic!("booo"),
         }