FEAT: Add benchmarks for .extend()

Cargo.toml

@@ -30,6 +30,11 @@ version = "1.0"
 
 [dev-dependencies]
 matches = { version = "0.1" }
+bencher = "0.1.4"
+
+[[bench]]
+name = "extend"
+harness = false
 
 [features]
 default = ["std"]

benches/extend.rs

@@ -0,0 +1,43 @@
+
+extern crate arrayvec;
+#[macro_use] extern crate bencher;
+
+use arrayvec::ArrayVec;
+
+use bencher::Bencher;
+
+fn extend_with_constant(b: &mut Bencher) {
+    let mut v = ArrayVec::<[u8; 512]>::new();
+    let cap = v.capacity();
+    b.iter(|| {
+        v.clear();
+        v.extend((0..cap).map(|_| 1));
+        v[0]
+    });
+    b.bytes = v.capacity() as u64;
+}
+
+fn extend_with_range(b: &mut Bencher) {
+    let mut v = ArrayVec::<[u8; 512]>::new();
+    let cap = v.capacity();
+    b.iter(|| {
+        v.clear();
+        v.extend((0..cap).map(|x| x as _));
+        v[0]
+    });
+    b.bytes = v.capacity() as u64;
+}
+
+fn extend_with_slice(b: &mut Bencher) {
+    let mut v = ArrayVec::<[u8; 512]>::new();
+    let data = [1; 512];
+    b.iter(|| {
+        v.clear();
+        v.extend(data.iter().cloned());
+        v[0]
+    });
+    b.bytes = v.capacity() as u64;
+}
+
+benchmark_group!(benches, extend_with_constant, extend_with_range, extend_with_slice);
+benchmark_main!(benches);