]>
git.proxmox.com Git - rustc.git/blob - src/libcore/nonzero.rs
59819fd500d1d25235ae95a1306c9a8504f60132
1 // Copyright 2012-2014 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.
11 //! Exposes the NonZero lang item which provides optimization hints.
16 use ops
::CoerceUnsized
;
18 /// Unsafe trait to indicate what types are usable with the NonZero struct
19 pub unsafe trait Zeroable {}
21 unsafe impl<T
:?Sized
> Zeroable
for *const T {}
22 unsafe impl<T
:?Sized
> Zeroable
for *mut T {}
23 unsafe impl Zeroable
for isize {}
24 unsafe impl Zeroable
for usize {}
25 unsafe impl Zeroable
for i8 {}
26 unsafe impl Zeroable
for u8 {}
27 unsafe impl Zeroable
for i16 {}
28 unsafe impl Zeroable
for u16 {}
29 unsafe impl Zeroable
for i32 {}
30 unsafe impl Zeroable
for u32 {}
31 unsafe impl Zeroable
for i64 {}
32 unsafe impl Zeroable
for u64 {}
34 /// A wrapper type for raw pointers and integers that will never be
35 /// NULL or 0 that might allow certain optimizations.
37 #[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Debug, Hash)]
38 #[unstable(feature = "core")]
39 pub struct NonZero
<T
: Zeroable
>(T
);
41 impl<T
: Zeroable
> NonZero
<T
> {
42 /// Creates an instance of NonZero with the provided value.
43 /// You must indeed ensure that the value is actually "non-zero".
45 pub unsafe fn new(inner
: T
) -> NonZero
<T
> {
50 impl<T
: Zeroable
> Deref
for NonZero
<T
> {
54 fn deref
<'a
>(&'a
self) -> &'a T
{
55 let NonZero(ref inner
) = *self;
61 impl<T
: Zeroable
+CoerceUnsized
<U
>, U
: Zeroable
> CoerceUnsized
<NonZero
<U
>> for NonZero
<T
> {}