vendor/itertools-0.8.2/benches/tuple_combinations.rs

   1 #![feature(test)]
   2
   3 extern crate test;
   4 extern crate itertools;
   5
   6 use test::{black_box, Bencher};
   7 use itertools::Itertools;
   8
   9 // approximate 100_000 iterations for each combination
  10 const N1: usize = 100_000;
  11 const N2: usize = 448;
  12 const N3: usize = 86;
  13 const N4: usize = 41;
  14
  15 #[bench]
  16 fn comb_for1(b: &mut Bencher) {
  17     b.iter(|| {
  18         for i in 0..N1 {
  19             black_box(i);
  20         }
  21     });
  22 }
  23
  24 #[bench]
  25 fn comb_for2(b: &mut Bencher) {
  26     b.iter(|| {
  27         for i in 0..N2 {
  28             for j in (i + 1)..N2 {
  29                 black_box(i + j);
  30             }
  31         }
  32     });
  33 }
  34
  35 #[bench]
  36 fn comb_for3(b: &mut Bencher) {
  37     b.iter(|| {
  38         for i in 0..N3 {
  39             for j in (i + 1)..N3 {
  40                 for k in (j + 1)..N3 {
  41                     black_box(i + j + k);
  42                 }
  43             }
  44         }
  45     });
  46 }
  47
  48 #[bench]
  49 fn comb_for4(b: &mut Bencher) {
  50     b.iter(|| {
  51         for i in 0..N4 {
  52             for j in (i + 1)..N4 {
  53                 for k in (j + 1)..N4 {
  54                     for l in (k + 1)..N4 {
  55                         black_box(i + j + k + l);
  56                     }
  57                 }
  58             }
  59         }
  60     });
  61 }
  62
  63 #[bench]
  64 fn comb_c1(b: &mut Bencher) {
  65     b.iter(|| {
  66         for (i,) in (0..N1).tuple_combinations() {
  67             black_box(i);
  68         }
  69     });
  70 }
  71
  72 #[bench]
  73 fn comb_c2(b: &mut Bencher) {
  74     b.iter(|| {
  75         for (i, j) in (0..N2).tuple_combinations() {
  76             black_box(i + j);
  77         }
  78     });
  79 }
  80
  81 #[bench]
  82 fn comb_c3(b: &mut Bencher) {
  83     b.iter(|| {
  84         for (i, j, k) in (0..N3).tuple_combinations() {
  85             black_box(i + j + k);
  86         }
  87     });
  88 }
  89
  90 #[bench]
  91 fn comb_c4(b: &mut Bencher) {
  92     b.iter(|| {
  93         for (i, j, k, l) in (0..N4).tuple_combinations() {
  94             black_box(i + j + k + l);
  95         }
  96     });
  97 }