1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 #![unstable(feature = "collections_range", reason = "was just added")]
15 use core::option::Option::{self, None, Some};
16 use core::ops::{RangeFull, Range, RangeTo, RangeFrom};
18 /// **RangeArgument** is implemented by Rust's built-in range types, produced
19 /// by range syntax like `..`, `a..`, `..b` or `c..d`.
20 pub trait RangeArgument<T> {
21 /// Start index (inclusive)
23 /// Return start value if present, else `None`.
24 fn start(&self) -> Option<&T> { None }
26 /// End index (exclusive)
28 /// Return end value if present, else `None`.
29 fn end(&self) -> Option<&T> { None }
33 impl<T> RangeArgument<T> for RangeFull {}
35 impl<T> RangeArgument<T> for RangeFrom<T> {
36 fn start(&self) -> Option<&T> { Some(&self.start) }
39 impl<T> RangeArgument<T> for RangeTo<T> {
40 fn end(&self) -> Option<&T> { Some(&self.end) }
43 impl<T> RangeArgument<T> for Range<T> {
44 fn start(&self) -> Option<&T> { Some(&self.start) }
45 fn end(&self) -> Option<&T> { Some(&self.end) }