1 use criterion::{black_box, criterion_group, criterion_main, Criterion};
2 use itertools::Itertools;
3 
4 // approximate 100_000 iterations for each combination
5 const N1: usize = 100_000;
6 const N2: usize = 448;
7 const N3: usize = 86;
8 const N4: usize = 41;
9 
tuple_comb_for1(c: &mut Criterion)10 fn tuple_comb_for1(c: &mut Criterion) {
11     c.bench_function("tuple comb for1", move |b| {
12         b.iter(|| {
13             for i in 0..N1 {
14                 black_box(i);
15             }
16         })
17     });
18 }
19 
tuple_comb_for2(c: &mut Criterion)20 fn tuple_comb_for2(c: &mut Criterion) {
21     c.bench_function("tuple comb for2", move |b| {
22         b.iter(|| {
23             for i in 0..N2 {
24                 for j in (i + 1)..N2 {
25                     black_box(i + j);
26                 }
27             }
28         })
29     });
30 }
31 
tuple_comb_for3(c: &mut Criterion)32 fn tuple_comb_for3(c: &mut Criterion) {
33     c.bench_function("tuple comb for3", move |b| {
34         b.iter(|| {
35             for i in 0..N3 {
36                 for j in (i + 1)..N3 {
37                     for k in (j + 1)..N3 {
38                         black_box(i + j + k);
39                     }
40                 }
41             }
42         })
43     });
44 }
45 
tuple_comb_for4(c: &mut Criterion)46 fn tuple_comb_for4(c: &mut Criterion) {
47     c.bench_function("tuple comb for4", move |b| {
48         b.iter(|| {
49             for i in 0..N4 {
50                 for j in (i + 1)..N4 {
51                     for k in (j + 1)..N4 {
52                         for l in (k + 1)..N4 {
53                             black_box(i + j + k + l);
54                         }
55                     }
56                 }
57             }
58         })
59     });
60 }
61 
tuple_comb_c1(c: &mut Criterion)62 fn tuple_comb_c1(c: &mut Criterion) {
63     c.bench_function("tuple comb c1", move |b| {
64         b.iter(|| {
65             for (i,) in (0..N1).tuple_combinations() {
66                 black_box(i);
67             }
68         })
69     });
70 }
71 
tuple_comb_c2(c: &mut Criterion)72 fn tuple_comb_c2(c: &mut Criterion) {
73     c.bench_function("tuple comb c2", move |b| {
74         b.iter(|| {
75             for (i, j) in (0..N2).tuple_combinations() {
76                 black_box(i + j);
77             }
78         })
79     });
80 }
81 
tuple_comb_c3(c: &mut Criterion)82 fn tuple_comb_c3(c: &mut Criterion) {
83     c.bench_function("tuple comb c3", move |b| {
84         b.iter(|| {
85             for (i, j, k) in (0..N3).tuple_combinations() {
86                 black_box(i + j + k);
87             }
88         })
89     });
90 }
91 
tuple_comb_c4(c: &mut Criterion)92 fn tuple_comb_c4(c: &mut Criterion) {
93     c.bench_function("tuple comb c4", move |b| {
94         b.iter(|| {
95             for (i, j, k, l) in (0..N4).tuple_combinations() {
96                 black_box(i + j + k + l);
97             }
98         })
99     });
100 }
101 
102 criterion_group!(
103     benches,
104     tuple_comb_for1,
105     tuple_comb_for2,
106     tuple_comb_for3,
107     tuple_comb_for4,
108     tuple_comb_c1,
109     tuple_comb_c2,
110     tuple_comb_c3,
111     tuple_comb_c4,
112 );
113 criterion_main!(benches);
114