2 #![feature(slice_patterns)]
4 fn match_vecs<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {
6 (&[], &[]) => "both empty",
7 (&[], &[..]) | (&[..], &[]) => "one empty",
8 (&[..], &[..]) => "both non-empty"
12 fn match_vecs_cons<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {
14 (&[], &[]) => "both empty",
15 (&[], &[_, ..]) | (&[_, ..], &[]) => "one empty",
16 (&[_, ..], &[_, ..]) => "both non-empty"
20 fn match_vecs_snoc<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {
22 (&[], &[]) => "both empty",
23 (&[], &[.., _]) | (&[.., _], &[]) => "one empty",
24 (&[.., _], &[.., _]) => "both non-empty"
28 fn match_nested_vecs_cons<'a, T>(l1: Option<&'a [T]>, l2: Result<&'a [T], ()>) -> &'static str {
30 (Some(&[]), Ok(&[])) => "Some(empty), Ok(empty)",
31 (Some(&[_, ..]), Ok(_)) | (Some(&[_, ..]), Err(())) => "Some(non-empty), any",
32 (None, Ok(&[])) | (None, Err(())) | (None, Ok(&[_])) => "None, Ok(less than one element)",
33 (None, Ok(&[_, _, ..])) => "None, Ok(at least two elements)",
38 fn match_nested_vecs_snoc<'a, T>(l1: Option<&'a [T]>, l2: Result<&'a [T], ()>) -> &'static str {
40 (Some(&[]), Ok(&[])) => "Some(empty), Ok(empty)",
41 (Some(&[.., _]), Ok(_)) | (Some(&[.., _]), Err(())) => "Some(non-empty), any",
42 (None, Ok(&[])) | (None, Err(())) | (None, Ok(&[_])) => "None, Ok(less than one element)",
43 (None, Ok(&[.., _, _])) => "None, Ok(at least two elements)",
49 assert_eq!(match_vecs(&[1, 2], &[2, 3]), "both non-empty");
50 assert_eq!(match_vecs(&[], &[1, 2, 3, 4]), "one empty");
51 assert_eq!(match_vecs::<usize>(&[], &[]), "both empty");
52 assert_eq!(match_vecs(&[1, 2, 3], &[]), "one empty");
54 assert_eq!(match_vecs_cons(&[1, 2], &[2, 3]), "both non-empty");
55 assert_eq!(match_vecs_cons(&[], &[1, 2, 3, 4]), "one empty");
56 assert_eq!(match_vecs_cons::<usize>(&[], &[]), "both empty");
57 assert_eq!(match_vecs_cons(&[1, 2, 3], &[]), "one empty");
59 assert_eq!(match_vecs_snoc(&[1, 2], &[2, 3]), "both non-empty");
60 assert_eq!(match_vecs_snoc(&[], &[1, 2, 3, 4]), "one empty");
61 assert_eq!(match_vecs_snoc::<usize>(&[], &[]), "both empty");
62 assert_eq!(match_vecs_snoc(&[1, 2, 3], &[]), "one empty");
64 assert_eq!(match_nested_vecs_cons(None, Ok::<&[_], ()>(&[4_usize, 2_usize])),
65 "None, Ok(at least two elements)");
66 assert_eq!(match_nested_vecs_cons::<usize>(None, Err(())), "None, Ok(less than one element)");
67 assert_eq!(match_nested_vecs_cons::<bool>(Some::<&[_]>(&[]), Ok::<&[_], ()>(&[])),
68 "Some(empty), Ok(empty)");
69 assert_eq!(match_nested_vecs_cons(Some::<&[_]>(&[1]), Err(())), "Some(non-empty), any");
70 assert_eq!(match_nested_vecs_cons(Some::<&[_]>(&[(42, ())]), Ok::<&[_], ()>(&[(1, ())])),
71 "Some(non-empty), any");
73 assert_eq!(match_nested_vecs_snoc(None, Ok::<&[_], ()>(&[4_usize, 2_usize])),
74 "None, Ok(at least two elements)");
75 assert_eq!(match_nested_vecs_snoc::<usize>(None, Err(())), "None, Ok(less than one element)");
76 assert_eq!(match_nested_vecs_snoc::<bool>(Some::<&[_]>(&[]), Ok::<&[_], ()>(&[])),
77 "Some(empty), Ok(empty)");
78 assert_eq!(match_nested_vecs_snoc(Some::<&[_]>(&[1]), Err(())), "Some(non-empty), any");
79 assert_eq!(match_nested_vecs_snoc(Some::<&[_]>(&[(42, ())]), Ok::<&[_], ()>(&[(1, ())])),
80 "Some(non-empty), any");