Vendor dependencies

Let's see how I like this workflow.

vendor/once_cell/examples/bench_vs_lazy_static.rs

@@ -0,0 +1,51 @@
+use lazy_static::lazy_static;
+use once_cell::sync::Lazy;
+
+const N_THREADS: usize = 32;
+const N_ROUNDS: usize = 100_000_000;
+
+static ONCE_CELL: Lazy<Vec<String>> = Lazy::new(|| vec!["Spica".to_string(), "Hoyten".to_string()]);
+
+lazy_static! {
+    static ref LAZY_STATIC: Vec<String> = vec!["Spica".to_string(), "Hoyten".to_string()];
+}
+
+fn main() {
+    let once_cell = {
+        let start = std::time::Instant::now();
+        let threads = (0..N_THREADS)
+            .map(|_| std::thread::spawn(move || thread_once_cell()))
+            .collect::<Vec<_>>();
+        for thread in threads {
+            thread.join().unwrap();
+        }
+        start.elapsed()
+    };
+    let lazy_static = {
+        let start = std::time::Instant::now();
+        let threads = (0..N_THREADS)
+            .map(|_| std::thread::spawn(move || thread_lazy_static()))
+            .collect::<Vec<_>>();
+        for thread in threads {
+            thread.join().unwrap();
+        }
+        start.elapsed()
+    };
+
+    println!("once_cell:   {:?}", once_cell);
+    println!("lazy_static: {:?}", lazy_static);
+}
+
+fn thread_once_cell() {
+    for _ in 0..N_ROUNDS {
+        let len = ONCE_CELL.len();
+        assert_eq!(len, 2)
+    }
+}
+
+fn thread_lazy_static() {
+    for _ in 0..N_ROUNDS {
+        let len = LAZY_STATIC.len();
+        assert_eq!(len, 2)
+    }
+}