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Steve Klabnik
665aed059a
Rather than port each individual change to these files, for the release, I just waited to do it all at the end, in this commit. Since individual comits made it to master, everyone should get proper credit in the main tree, and AUTHORS includes those whose changes are here.
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% Slice patterns
If you want to match against a slice or array, you can use & with the
slice_patterns feature:
#![feature(slice_patterns)]
fn main() {
let v = vec!["match_this", "1"];
match &v[..] {
["match_this", second] => println!("The second element is {}", second),
_ => {},
}
}
The advanced_slice_patterns gate lets you use .. to indicate any number of
elements inside a pattern matching a slice. This wildcard can only be used once
for a given array. If there's an identifier before the .., the result of the
slice will be bound to that name. For example:
#![feature(advanced_slice_patterns, slice_patterns)]
fn is_symmetric(list: &[u32]) -> bool {
match list {
[] | [_] => true,
[x, inside.., y] if x == y => is_symmetric(inside),
_ => false
}
}
fn main() {
let sym = &[0, 1, 4, 2, 4, 1, 0];
assert!(is_symmetric(sym));
let not_sym = &[0, 1, 7, 2, 4, 1, 0];
assert!(!is_symmetric(not_sym));
}