ну запустите cargo bench, вам жалко штоле
running 19 tests
test indexed::test::go_backwards ... bench: 208,231 ns/iter (+/- 50,023)
test indexed::test::go_forward ... bench: 193,297 ns/iter (+/- 46,390)
test original::go_backwards_fold ... bench: 378,718 ns/iter (+/- 87,252)
test original::go_backwards_for ... bench: 371,455 ns/iter (+/- 126,100)
test original::go_backwards_sum ... bench: 367,536 ns/iter (+/- 99,276)
test original::go_forward_fold ... bench: 115,149 ns/iter (+/- 12,568)
test original::go_forward_for ... bench: 112,728 ns/iter (+/- 11,687)
test original::straight_izip_fold ... bench: 115,524 ns/iter (+/- 19,532)
test original::straight_izip_for ... bench: 115,966 ns/iter (+/- 18,435)
test original::straight_zip_fold ... bench: 118,023 ns/iter (+/- 17,297)
test original::straight_zip_for ... bench: 115,547 ns/iter (+/- 24,050)
test straightforward::test::go_backwards ... bench: 123,300 ns/iter (+/- 29,099)
test straightforward::test::go_backwards_for ... bench: 121,229 ns/iter (+/- 14,298)
test straightforward::test::go_forward ... bench: 117,571 ns/iter (+/- 23,469)
test straightforward::test::go_forward_for ... bench: 116,177 ns/iter (+/- 16,713)
test zipped::test::go_backwards ... bench: 345,277 ns/iter (+/- 52,363)
test zipped::test::go_backwards_for ... bench: 364,224 ns/iter (+/- 96,323)
test zipped::test::go_forward_fold ... bench: 113,547 ns/iter (+/- 13,052)
test zipped::test::go_forward_for ... bench: 115,215 ns/iter (+/- 13,792)