1f70acbf4c
This gets rid of the 'experimental' level, removes the non-staged_api case (i.e. stability levels for out-of-tree crates), and lets the staged_api attributes use 'unstable' and 'deprecated' lints. This makes the transition period to the full feature staging design a bit nicer.
56 lines
1.7 KiB
Rust
56 lines
1.7 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.
|
|
|
|
//! Exposes the NonZero lang item which provides optimization hints.
|
|
|
|
use ops::Deref;
|
|
|
|
/// Unsafe trait to indicate what types are usable with the NonZero struct
|
|
pub unsafe trait Zeroable {}
|
|
|
|
unsafe impl<T> Zeroable for *const T {}
|
|
unsafe impl<T> Zeroable for *mut T {}
|
|
unsafe impl Zeroable for int {}
|
|
unsafe impl Zeroable for uint {}
|
|
unsafe impl Zeroable for i8 {}
|
|
unsafe impl Zeroable for u8 {}
|
|
unsafe impl Zeroable for i16 {}
|
|
unsafe impl Zeroable for u16 {}
|
|
unsafe impl Zeroable for i32 {}
|
|
unsafe impl Zeroable for u32 {}
|
|
unsafe impl Zeroable for i64 {}
|
|
unsafe impl Zeroable for u64 {}
|
|
|
|
/// A wrapper type for raw pointers and integers that will never be
|
|
/// NULL or 0 that might allow certain optimizations.
|
|
#[lang="non_zero"]
|
|
#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Show)]
|
|
#[unstable]
|
|
pub struct NonZero<T: Zeroable>(T);
|
|
|
|
impl<T: Zeroable> NonZero<T> {
|
|
/// Create an instance of NonZero with the provided value.
|
|
/// You must indeed ensure that the value is actually "non-zero".
|
|
#[inline(always)]
|
|
pub unsafe fn new(inner: T) -> NonZero<T> {
|
|
NonZero(inner)
|
|
}
|
|
}
|
|
|
|
impl<T: Zeroable> Deref for NonZero<T> {
|
|
type Target = T;
|
|
|
|
#[inline]
|
|
fn deref<'a>(&'a self) -> &'a T {
|
|
let NonZero(ref inner) = *self;
|
|
inner
|
|
}
|
|
}
|