Add missing black_box in String benchmarks

library/alloctests/benches/string.rs

@@ -4,7 +4,7 @@ use test::{Bencher, black_box};
 
 #[bench]
 fn bench_with_capacity(b: &mut Bencher) {
-    b.iter(|| String::with_capacity(100));
+    b.iter(|| String::with_capacity(black_box(100)));
 }
 
 #[bench]
@@ -12,7 +12,8 @@ fn bench_push_str(b: &mut Bencher) {
     let s = "ศไทย中华Việt Nam; Mary had a little lamb, Little lamb";
     b.iter(|| {
         let mut r = String::new();
-        r.push_str(s);
+        black_box(&mut r).push_str(black_box(s));
+        r
     });
 }
 
@@ -24,8 +25,9 @@ fn bench_push_str_one_byte(b: &mut Bencher) {
     b.iter(|| {
         let mut r = String::new();
         for _ in 0..REPETITIONS {
-            r.push_str("a")
+            black_box(&mut r).push_str(black_box("a"));
         }
+        r
     });
 }
 
@@ -35,8 +37,9 @@ fn bench_push_char_one_byte(b: &mut Bencher) {
     b.iter(|| {
         let mut r = String::new();
         for _ in 0..REPETITIONS {
-            r.push('a')
+            black_box(&mut r).push(black_box('a'));
         }
+        r
     });
 }
 
@@ -46,8 +49,9 @@ fn bench_push_char_two_bytes(b: &mut Bencher) {
     b.iter(|| {
         let mut r = String::new();
         for _ in 0..REPETITIONS {
-            r.push('â')
+            black_box(&mut r).push(black_box('â'));
         }
+        r
     });
 }
 
@@ -57,34 +61,26 @@ fn from_utf8_lossy_100_ascii(b: &mut Bencher) {
               Lorem ipsum dolor sit amet, consectetur. ";
 
     assert_eq!(100, s.len());
-    b.iter(|| {
-        let _ = String::from_utf8_lossy(s);
-    });
+    b.iter(|| String::from_utf8_lossy(black_box(s)));
 }
 
 #[bench]
 fn from_utf8_lossy_100_multibyte(b: &mut Bencher) {
     let s = "𐌀𐌖𐌋𐌄𐌑𐌉ปรدولة الكويتทศไทย中华𐍅𐌿𐌻𐍆𐌹𐌻𐌰".as_bytes();
     assert_eq!(100, s.len());
-    b.iter(|| {
-        let _ = String::from_utf8_lossy(s);
-    });
+    b.iter(|| String::from_utf8_lossy(black_box(s)));
 }
 
 #[bench]
 fn from_utf8_lossy_invalid(b: &mut Bencher) {
     let s = b"Hello\xC0\x80 There\xE6\x83 Goodbye";
-    b.iter(|| {
-        let _ = String::from_utf8_lossy(s);
-    });
+    b.iter(|| String::from_utf8_lossy(black_box(s)));
 }
 
 #[bench]
 fn from_utf8_lossy_100_invalid(b: &mut Bencher) {
     let s = repeat(0xf5).take(100).collect::<Vec<_>>();
-    b.iter(|| {
-        let _ = String::from_utf8_lossy(&s);
-    });
+    b.iter(|| String::from_utf8_lossy(black_box(&s)));
 }
 
 #[bench]
@@ -96,8 +92,8 @@ fn bench_exact_size_shrink_to_fit(b: &mut Bencher) {
     r.push_str(s);
     assert_eq!(r.len(), r.capacity());
     b.iter(|| {
-        let mut r = String::with_capacity(s.len());
-        r.push_str(s);
+        let mut r = String::with_capacity(black_box(s.len()));
+        r.push_str(black_box(s));
         r.shrink_to_fit();
         r
     });
@@ -107,21 +103,21 @@ fn bench_exact_size_shrink_to_fit(b: &mut Bencher) {
 fn bench_from_str(b: &mut Bencher) {
     let s = "Hello there, the quick brown fox jumped over the lazy dog! \
              Lorem ipsum dolor sit amet, consectetur. ";
-    b.iter(|| String::from(s))
+    b.iter(|| String::from(black_box(s)))
 }
 
 #[bench]
 fn bench_from(b: &mut Bencher) {
     let s = "Hello there, the quick brown fox jumped over the lazy dog! \
              Lorem ipsum dolor sit amet, consectetur. ";
-    b.iter(|| String::from(s))
+    b.iter(|| String::from(black_box(s)))
 }
 
 #[bench]
 fn bench_to_string(b: &mut Bencher) {
     let s = "Hello there, the quick brown fox jumped over the lazy dog! \
              Lorem ipsum dolor sit amet, consectetur. ";
-    b.iter(|| s.to_string())
+    b.iter(|| black_box(s).to_string())
 }
 
 #[bench]
@@ -129,7 +125,7 @@ fn bench_insert_char_short(b: &mut Bencher) {
     let s = "Hello, World!";
     b.iter(|| {
         let mut x = String::from(s);
-        black_box(&mut x).insert(6, black_box(' '));
+        black_box(&mut x).insert(black_box(6), black_box(' '));
         x
     })
 }
@@ -139,7 +135,7 @@ fn bench_insert_char_long(b: &mut Bencher) {
     let s = "Hello, World!";
     b.iter(|| {
         let mut x = String::from(s);
-        black_box(&mut x).insert(6, black_box('❤'));
+        black_box(&mut x).insert(black_box(6), black_box('❤'));
         x
     })
 }
@@ -149,7 +145,7 @@ fn bench_insert_str_short(b: &mut Bencher) {
     let s = "Hello, World!";
     b.iter(|| {
         let mut x = String::from(s);
-        black_box(&mut x).insert_str(6, black_box(" "));
+        black_box(&mut x).insert_str(black_box(6), black_box(" "));
         x
     })
 }
@@ -159,7 +155,7 @@ fn bench_insert_str_long(b: &mut Bencher) {
     let s = "Hello, World!";
     b.iter(|| {
         let mut x = String::from(s);
-        black_box(&mut x).insert_str(6, black_box(" rustic "));
+        black_box(&mut x).insert_str(black_box(6), black_box(" rustic "));
         x
     })
 }