tamer: benches/iter.rs: Basic benchmark

This was forgotten in the previous commit and exists simply to ensure that
the TripIter doesn't add any significant overhead.  The tests are
a handful of nanoseconds apart, on my machine.

tamer/benches/iter.rs

@@ -0,0 +1,59 @@
+// Comparisons between Rust built-ins and memchr.
+//
+//  Copyright (C) 2014-2021 Ryan Specialty Group, LLC.
+//
+//  This file is part of TAME.
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#![feature(test)]
+
+extern crate tamer;
+extern crate test;
+
+use tamer::iter::into_iter_while_ok;
+use test::Bencher;
+
+mod trip {
+    use super::*;
+
+    #[bench]
+    fn baseline_map_while(bench: &mut Bencher) {
+        let mut data = (0..100).map(Ok).collect::<Vec<_>>();
+        data.push(Err("trip"));
+
+        bench.iter(|| {
+            data.clone()
+                .into_iter()
+                .map_while(Result::ok)
+                .for_each(drop);
+        });
+    }
+
+    // Note that these aren't comparable feature-wise, since the above
+    // doesn't give us access to the underlying iterator.  This is just to
+    // ensure that performance is at least pretty close, despite it doing a
+    // little more work.  (And it is.)
+    #[bench]
+    fn trip_iter(bench: &mut Bencher) {
+        let mut data = (0..100).map(Ok).collect::<Vec<_>>();
+        data.push(Err("trip"));
+
+        bench.iter(|| {
+            into_iter_while_ok(data.clone(), |iter| {
+                iter.for_each(drop);
+            })
+        });
+    }
+}