Add first benchmark

Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "nvector"
+version = "0.1.0"
+authors = ["Armin Becher <armin.becher@methodpark.de>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+criterion = "0.3.1"
+
+[[bench]]
+name = "two_dim_array"
+harness = false

benches/two_dim_array.rs

@@ -0,0 +1,20 @@
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+
+fn init(x: usize, y: usize) -> Vec<Vec<u32>> {
+    vec![vec![42; x]; y]
+}
+
+fn init_flat(x: usize, y: usize) -> Vec<u32> {
+    vec![42; x * y]
+}
+
+
+fn criterion_benchmark(c: &mut Criterion) {
+    c.bench_function("Init  20x20", |b| b.iter(|| init(black_box(20), black_box(20))));
+    c.bench_function("Init flat  20x20", |b| b.iter(|| init_flat(black_box(20), black_box(20))));
+    c.bench_function("Init  2000x2000", |b| b.iter(|| init(black_box(2000), black_box(2000))));
+    c.bench_function("Init flat  2000x2000", |b| b.iter(|| init_flat(black_box(2000), black_box(2000))));
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);