rust/src/libcore/array.rs
Aaron Turon b94bcbf56e Stabilize cmp
This patch marks `PartialEq`, `Eq`, `PartialOrd`, and `Ord` as
`#[stable]`, as well as the majorify of manual implementaitons of these
traits. The traits match the [reform
RFC](https://github.com/rust-lang/rfcs/pull/439).

Along the way, two changes are made:

* The recently-added type parameters for `Ord` and `Eq` are
  removed. These were mistakenly added while adding them to `PartialOrd`
  and `PartialEq`, but they don't make sense given the laws that are
  required for (and use cases for) `Ord` and `Eq`.

* More explicit laws are added for `PartialEq` and `PartialOrd`,
  connecting them to their associated mathematical concepts.

In the future, many of the impls should be generalized; see
since generalizing later is not a breaking change.

[breaking-change]
2014-12-30 14:44:26 -08:00

120 lines
3.9 KiB
Rust

// Copyright 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.
//! Implementations of things like `Eq` for fixed-length arrays
//! up to a certain length. Eventually we should able to generalize
//! to all lengths.
#![experimental] // not yet reviewed
use clone::Clone;
use cmp::{PartialEq, Eq, PartialOrd, Ord, Ordering};
use fmt;
use kinds::Copy;
use ops::Deref;
use option::Option;
// macro for implementing n-ary tuple functions and operations
macro_rules! array_impls {
($($N:expr)+) => {
$(
#[stable]
impl<T:Copy> Clone for [T, ..$N] {
fn clone(&self) -> [T, ..$N] {
*self
}
}
#[unstable = "waiting for Show to stabilize"]
impl<T:fmt::Show> fmt::Show for [T, ..$N] {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Show::fmt(&self[], f)
}
}
#[stable]
impl<A, B> PartialEq<[B, ..$N]> for [A, ..$N] where A: PartialEq<B> {
#[inline]
fn eq(&self, other: &[B, ..$N]) -> bool {
self[] == other[]
}
#[inline]
fn ne(&self, other: &[B, ..$N]) -> bool {
self[] != other[]
}
}
#[stable]
impl<'a, A, B, Rhs> PartialEq<Rhs> for [A, ..$N] where
A: PartialEq<B>,
Rhs: Deref<[B]>,
{
#[inline(always)]
fn eq(&self, other: &Rhs) -> bool { PartialEq::eq(self[], &**other) }
#[inline(always)]
fn ne(&self, other: &Rhs) -> bool { PartialEq::ne(self[], &**other) }
}
#[stable]
impl<'a, A, B, Lhs> PartialEq<[B, ..$N]> for Lhs where
A: PartialEq<B>,
Lhs: Deref<[A]>
{
#[inline(always)]
fn eq(&self, other: &[B, ..$N]) -> bool { PartialEq::eq(&**self, other[]) }
#[inline(always)]
fn ne(&self, other: &[B, ..$N]) -> bool { PartialEq::ne(&**self, other[]) }
}
#[stable]
impl<T:Eq> Eq for [T, ..$N] { }
#[stable]
impl<T:PartialOrd> PartialOrd for [T, ..$N] {
#[inline]
fn partial_cmp(&self, other: &[T, ..$N]) -> Option<Ordering> {
PartialOrd::partial_cmp(&self[], &other[])
}
#[inline]
fn lt(&self, other: &[T, ..$N]) -> bool {
PartialOrd::lt(&self[], &other[])
}
#[inline]
fn le(&self, other: &[T, ..$N]) -> bool {
PartialOrd::le(&self[], &other[])
}
#[inline]
fn ge(&self, other: &[T, ..$N]) -> bool {
PartialOrd::ge(&self[], &other[])
}
#[inline]
fn gt(&self, other: &[T, ..$N]) -> bool {
PartialOrd::gt(&self[], &other[])
}
}
#[stable]
impl<T:Ord> Ord for [T, ..$N] {
#[inline]
fn cmp(&self, other: &[T, ..$N]) -> Ordering {
Ord::cmp(&self[], &other[])
}
}
)+
}
}
array_impls! {
0 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
}