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.
10 #![unstable(feature = "collections_range", reason = "was just added")]
14 use core
::option
::Option
::{self, None, Some}
;
15 use core
::ops
::{RangeFull, Range, RangeTo, RangeFrom}
;
17 /// **RangeArgument** is implemented by Rust's built-in range types, produced
18 /// by range syntax like `..`, `a..`, `..b` or `c..d`.
19 pub trait RangeArgument
<T
> {
20 /// Start index (inclusive)
22 /// Return start value if present, else `None`.
23 fn start(&self) -> Option
<&T
> { None }
25 /// End index (exclusive)
27 /// Return end value if present, else `None`.
28 fn end(&self) -> Option
<&T
> { None }
32 impl<T
> RangeArgument
<T
> for RangeFull {}
34 impl<T
> RangeArgument
<T
> for RangeFrom
<T
> {
35 fn start(&self) -> Option
<&T
> { Some(&self.start) }
38 impl<T
> RangeArgument
<T
> for RangeTo
<T
> {
39 fn end(&self) -> Option
<&T
> { Some(&self.end) }
42 impl<T
> RangeArgument
<T
> for Range
<T
> {
43 fn start(&self) -> Option
<&T
> { Some(&self.start) }
44 fn end(&self) -> Option
<&T
> { Some(&self.end) }