rust/src/test/run-pass/operator-overloading.rs
Patrick Walton 6f99a27886 librustc: Implement lifetime elision.
This implements RFC 39. Omitted lifetimes in return values will now be
inferred to more useful defaults, and an error is reported if a lifetime
in a return type is omitted and one of the two lifetime elision rules
does not specify what it should be.

This primarily breaks two uncommon code patterns. The first is this:

    unsafe fn get_foo_out_of_thin_air() -> &Foo {
        ...
    }

This should be changed to:

    unsafe fn get_foo_out_of_thin_air() -> &'static Foo {
        ...
    }

The second pattern that needs to be changed is this:

    enum MaybeBorrowed<'a> {
        Borrowed(&'a str),
        Owned(String),
    }

    fn foo() -> MaybeBorrowed {
        Owned(format!("hello world"))
    }

Change code like this to:

    enum MaybeBorrowed<'a> {
        Borrowed(&'a str),
        Owned(String),
    }

    fn foo() -> MaybeBorrowed<'static> {
        Owned(format!("hello world"))
    }

Closes #15552.

[breaking-change]
2014-07-19 13:10:58 -07:00

79 lines
1.9 KiB
Rust

// Copyright 2012-2014 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.
use std::cmp;
use std::ops;
#[deriving(Show)]
struct Point {
x: int,
y: int
}
impl ops::Add<Point,Point> for Point {
fn add(&self, other: &Point) -> Point {
Point {x: self.x + (*other).x, y: self.y + (*other).y}
}
}
impl ops::Sub<Point,Point> for Point {
fn sub(&self, other: &Point) -> Point {
Point {x: self.x - (*other).x, y: self.y - (*other).y}
}
}
impl ops::Neg<Point> for Point {
fn neg(&self) -> Point {
Point {x: -self.x, y: -self.y}
}
}
impl ops::Not<Point> for Point {
fn not(&self) -> Point {
Point {x: !self.x, y: !self.y }
}
}
impl ops::Index<bool,int> for Point {
fn index(&self, x: &bool) -> &int {
if *x {
&self.x
} else {
&self.y
}
}
}
impl cmp::PartialEq for Point {
fn eq(&self, other: &Point) -> bool {
(*self).x == (*other).x && (*self).y == (*other).y
}
fn ne(&self, other: &Point) -> bool { !(*self).eq(other) }
}
pub fn main() {
let mut p = Point {x: 10, y: 20};
p = p + Point {x: 101, y: 102};
p = p - Point {x: 100, y: 100};
assert_eq!(p + Point {x: 5, y: 5}, Point {x: 16, y: 27});
assert_eq!(-p, Point {x: -11, y: -22});
assert_eq!(p[true], 11);
assert_eq!(p[false], 22);
let q = !p;
assert_eq!(q.x, !(p.x));
assert_eq!(q.y, !(p.y));
// Issue #1733
let result: proc(int) = proc(_)();
result(p[true]);
}