1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93
// Copyright 2015 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. #![unstable(feature = "collections_range", reason = "waiting for dust to settle on inclusive ranges", issue = "30877")] //! Range syntax. use core::option::Option::{self, None, Some}; use core::ops::{RangeFull, Range, RangeTo, RangeFrom}; /// **RangeArgument** is implemented by Rust's built-in range types, produced /// by range syntax like `..`, `a..`, `..b` or `c..d`. pub trait RangeArgument<T> { /// Start index (inclusive) /// /// Return start value if present, else `None`. /// /// # Examples /// /// ``` /// #![feature(collections)] /// #![feature(collections_range)] /// /// extern crate collections; /// /// # fn main() { /// use collections::range::RangeArgument; /// /// assert_eq!((..10).start(), None); /// assert_eq!((3..10).start(), Some(&3)); /// # } /// ``` fn start(&self) -> Option<&T> { None } /// End index (exclusive) /// /// Return end value if present, else `None`. /// /// # Examples /// /// ``` /// #![feature(collections)] /// #![feature(collections_range)] /// /// extern crate collections; /// /// # fn main() { /// use collections::range::RangeArgument; /// /// assert_eq!((3..).end(), None); /// assert_eq!((3..10).end(), Some(&10)); /// # } /// ``` fn end(&self) -> Option<&T> { None } } // FIXME add inclusive ranges to RangeArgument impl<T> RangeArgument<T> for RangeFull {} impl<T> RangeArgument<T> for RangeFrom<T> { fn start(&self) -> Option<&T> { Some(&self.start) } } impl<T> RangeArgument<T> for RangeTo<T> { fn end(&self) -> Option<&T> { Some(&self.end) } } impl<T> RangeArgument<T> for Range<T> { fn start(&self) -> Option<&T> { Some(&self.start) } fn end(&self) -> Option<&T> { Some(&self.end) } }