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// run-pass
fn match_vecs<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {
match (l1, l2) {
(&[], &[]) => "both empty",
(&[], &[..]) | (&[..], &[]) => "one empty",
(&[..], &[..]) => "both non-empty"
}
}
fn match_vecs_cons<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {
match (l1, l2) {
(&[], &[]) => "both empty",
(&[], &[_, ..]) | (&[_, ..], &[]) => "one empty",
(&[_, ..], &[_, ..]) => "both non-empty"
}
}
fn match_vecs_snoc<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {
match (l1, l2) {
(&[], &[]) => "both empty",
(&[], &[.., _]) | (&[.., _], &[]) => "one empty",
(&[.., _], &[.., _]) => "both non-empty"
}
}
fn match_nested_vecs_cons<'a, T>(l1: Option<&'a [T]>, l2: Result<&'a [T], ()>) -> &'static str {
match (l1, l2) {
(Some(&[]), Ok(&[])) => "Some(empty), Ok(empty)",
(Some(&[_, ..]), Ok(_)) | (Some(&[_, ..]), Err(())) => "Some(non-empty), any",
(None, Ok(&[])) | (None, Err(())) | (None, Ok(&[_])) => "None, Ok(less than one element)",
(None, Ok(&[_, _, ..])) => "None, Ok(at least two elements)",
_ => "other"
}
}
fn match_nested_vecs_snoc<'a, T>(l1: Option<&'a [T]>, l2: Result<&'a [T], ()>) -> &'static str {
match (l1, l2) {
(Some(&[]), Ok(&[])) => "Some(empty), Ok(empty)",
(Some(&[.., _]), Ok(_)) | (Some(&[.., _]), Err(())) => "Some(non-empty), any",
(None, Ok(&[])) | (None, Err(())) | (None, Ok(&[_])) => "None, Ok(less than one element)",
(None, Ok(&[.., _, _])) => "None, Ok(at least two elements)",
_ => "other"
}
}
fn main() {
assert_eq!(match_vecs(&[1, 2], &[2, 3]), "both non-empty");
assert_eq!(match_vecs(&[], &[1, 2, 3, 4]), "one empty");
assert_eq!(match_vecs::<usize>(&[], &[]), "both empty");
assert_eq!(match_vecs(&[1, 2, 3], &[]), "one empty");
assert_eq!(match_vecs_cons(&[1, 2], &[2, 3]), "both non-empty");
assert_eq!(match_vecs_cons(&[], &[1, 2, 3, 4]), "one empty");
assert_eq!(match_vecs_cons::<usize>(&[], &[]), "both empty");
assert_eq!(match_vecs_cons(&[1, 2, 3], &[]), "one empty");
assert_eq!(match_vecs_snoc(&[1, 2], &[2, 3]), "both non-empty");
assert_eq!(match_vecs_snoc(&[], &[1, 2, 3, 4]), "one empty");
assert_eq!(match_vecs_snoc::<usize>(&[], &[]), "both empty");
assert_eq!(match_vecs_snoc(&[1, 2, 3], &[]), "one empty");
assert_eq!(match_nested_vecs_cons(None, Ok::<&[_], ()>(&[4_usize, 2_usize])),
"None, Ok(at least two elements)");
assert_eq!(match_nested_vecs_cons::<usize>(None, Err(())), "None, Ok(less than one element)");
assert_eq!(match_nested_vecs_cons::<bool>(Some::<&[_]>(&[]), Ok::<&[_], ()>(&[])),
"Some(empty), Ok(empty)");
assert_eq!(match_nested_vecs_cons(Some::<&[_]>(&[1]), Err(())), "Some(non-empty), any");
assert_eq!(match_nested_vecs_cons(Some::<&[_]>(&[(42, ())]), Ok::<&[_], ()>(&[(1, ())])),
"Some(non-empty), any");
assert_eq!(match_nested_vecs_snoc(None, Ok::<&[_], ()>(&[4_usize, 2_usize])),
"None, Ok(at least two elements)");
assert_eq!(match_nested_vecs_snoc::<usize>(None, Err(())), "None, Ok(less than one element)");
assert_eq!(match_nested_vecs_snoc::<bool>(Some::<&[_]>(&[]), Ok::<&[_], ()>(&[])),
"Some(empty), Ok(empty)");
assert_eq!(match_nested_vecs_snoc(Some::<&[_]>(&[1]), Err(())), "Some(non-empty), any");
assert_eq!(match_nested_vecs_snoc(Some::<&[_]>(&[(42, ())]), Ok::<&[_], ()>(&[(1, ())])),
"Some(non-empty), any");
}
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