3 fn match_vecs<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {
5 (&[], &[]) => "both empty",
6 (&[], &[..]) | (&[..], &[]) => "one empty",
7 (&[..], &[..]) => "both non-empty"
11 fn match_vecs_cons<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {
13 (&[], &[]) => "both empty",
14 (&[], &[_, ..]) | (&[_, ..], &[]) => "one empty",
15 (&[_, ..], &[_, ..]) => "both non-empty"
19 fn match_vecs_snoc<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {
21 (&[], &[]) => "both empty",
22 (&[], &[.., _]) | (&[.., _], &[]) => "one empty",
23 (&[.., _], &[.., _]) => "both non-empty"
27 fn match_nested_vecs_cons<'a, T>(l1: Option<&'a [T]>, l2: Result<&'a [T], ()>) -> &'static str {
29 (Some(&[]), Ok(&[])) => "Some(empty), Ok(empty)",
30 (Some(&[_, ..]), Ok(_)) | (Some(&[_, ..]), Err(())) => "Some(non-empty), any",
31 (None, Ok(&[])) | (None, Err(())) | (None, Ok(&[_])) => "None, Ok(less than one element)",
32 (None, Ok(&[_, _, ..])) => "None, Ok(at least two elements)",
37 fn match_nested_vecs_snoc<'a, T>(l1: Option<&'a [T]>, l2: Result<&'a [T], ()>) -> &'static str {
39 (Some(&[]), Ok(&[])) => "Some(empty), Ok(empty)",
40 (Some(&[.., _]), Ok(_)) | (Some(&[.., _]), Err(())) => "Some(non-empty), any",
41 (None, Ok(&[])) | (None, Err(())) | (None, Ok(&[_])) => "None, Ok(less than one element)",
42 (None, Ok(&[.., _, _])) => "None, Ok(at least two elements)",
48 assert_eq!(match_vecs(&[1, 2], &[2, 3]), "both non-empty");
49 assert_eq!(match_vecs(&[], &[1, 2, 3, 4]), "one empty");
50 assert_eq!(match_vecs::<usize>(&[], &[]), "both empty");
51 assert_eq!(match_vecs(&[1, 2, 3], &[]), "one empty");
53 assert_eq!(match_vecs_cons(&[1, 2], &[2, 3]), "both non-empty");
54 assert_eq!(match_vecs_cons(&[], &[1, 2, 3, 4]), "one empty");
55 assert_eq!(match_vecs_cons::<usize>(&[], &[]), "both empty");
56 assert_eq!(match_vecs_cons(&[1, 2, 3], &[]), "one empty");
58 assert_eq!(match_vecs_snoc(&[1, 2], &[2, 3]), "both non-empty");
59 assert_eq!(match_vecs_snoc(&[], &[1, 2, 3, 4]), "one empty");
60 assert_eq!(match_vecs_snoc::<usize>(&[], &[]), "both empty");
61 assert_eq!(match_vecs_snoc(&[1, 2, 3], &[]), "one empty");
63 assert_eq!(match_nested_vecs_cons(None, Ok::<&[_], ()>(&[4_usize, 2_usize])),
64 "None, Ok(at least two elements)");
65 assert_eq!(match_nested_vecs_cons::<usize>(None, Err(())), "None, Ok(less than one element)");
66 assert_eq!(match_nested_vecs_cons::<bool>(Some::<&[_]>(&[]), Ok::<&[_], ()>(&[])),
67 "Some(empty), Ok(empty)");
68 assert_eq!(match_nested_vecs_cons(Some::<&[_]>(&[1]), Err(())), "Some(non-empty), any");
69 assert_eq!(match_nested_vecs_cons(Some::<&[_]>(&[(42, ())]), Ok::<&[_], ()>(&[(1, ())])),
70 "Some(non-empty), any");
72 assert_eq!(match_nested_vecs_snoc(None, Ok::<&[_], ()>(&[4_usize, 2_usize])),
73 "None, Ok(at least two elements)");
74 assert_eq!(match_nested_vecs_snoc::<usize>(None, Err(())), "None, Ok(less than one element)");
75 assert_eq!(match_nested_vecs_snoc::<bool>(Some::<&[_]>(&[]), Ok::<&[_], ()>(&[])),
76 "Some(empty), Ok(empty)");
77 assert_eq!(match_nested_vecs_snoc(Some::<&[_]>(&[1]), Err(())), "Some(non-empty), any");
78 assert_eq!(match_nested_vecs_snoc(Some::<&[_]>(&[(42, ())]), Ok::<&[_], ()>(&[(1, ())])),
79 "Some(non-empty), any");