rust/src/test/run-pass/issue-15104.rs
Jakub Wieczorek 9b3f9d9444 Change exhaustiveness analysis to permit multiple constructors per pattern
Slice patterns are different from the rest in that a single slice pattern
does not have a distinct constructor if it contains a variable-length subslice
pattern. For example, the pattern [a, b, ..tail] can match a slice of length 2, 3, 4
and so on.

As a result, the decision tree for exhaustiveness and redundancy analysis should
explore each of those constructors separately to determine if the pattern could be useful
when specialized for any of them.
2014-07-02 18:27:12 +02:00

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686 B
Rust

// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
fn main() {
assert_eq!(count_members(&[1, 2, 3, 4]), 4);
}
fn count_members(v: &[uint]) -> uint {
match v {
[] => 0,
[_] => 1,
[_x, ..xs] => 1 + count_members(xs)
}
}