99 lines
2.4 KiB
Rust
99 lines
2.4 KiB
Rust
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// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! Exposes the NonZero lang item which provides optimization hints.
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use cmp::Eq;
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use intrinsics;
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use kinds::Copy;
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use ops::Deref;
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use option::Option;
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use option::Option::Some;
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use ptr::{null, null_mut, RawPtr, RawMutPtr};
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/// A wrapper type for raw pointers and integers that will never be
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/// NULL or 0 that might allow certain optimizations.
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#[lang="non_zero"]
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#[deriving(Clone, PartialEq, Eq, PartialOrd)]
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#[experimental]
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pub struct NonZero<T>(T);
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impl<T> NonZero<T> {
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/// Create an instance of NonZero with the provided value.
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/// You must indeed ensure that the value is actually "non-zero".
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#[inline(always)]
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pub unsafe fn new(inner: T) -> NonZero<T> {
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NonZero(inner)
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}
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}
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impl<T: Copy> Copy for NonZero<T> {}
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impl<T> Deref<T> for NonZero<T> {
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#[inline]
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fn deref<'a>(&'a self) -> &'a T {
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let NonZero(ref inner) = *self;
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inner
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}
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}
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impl<T> RawPtr<T> for NonZero<*const T> {
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#[inline]
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fn null() -> NonZero<*const T> { NonZero(null()) }
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#[inline]
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fn is_null(&self) -> bool { false }
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#[inline]
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fn to_uint(&self) -> uint {
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**self as uint
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}
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#[inline]
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unsafe fn offset(self, count: int) -> NonZero<*const T> {
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NonZero(intrinsics::offset(*self, count))
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}
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#[inline]
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unsafe fn as_ref<'a>(&self) -> Option<&'a T> {
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Some(&***self)
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}
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}
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impl<T> RawPtr<T> for NonZero<*mut T> {
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#[inline]
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fn null() -> NonZero<*mut T> { NonZero(null_mut()) }
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#[inline]
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fn is_null(&self) -> bool { false }
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#[inline]
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fn to_uint(&self) -> uint {
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**self as uint
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}
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#[inline]
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unsafe fn offset(self, count: int) -> NonZero<*mut T> {
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NonZero(intrinsics::offset(*self as *const T, count) as *mut T)
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}
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#[inline]
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unsafe fn as_ref<'a>(&self) -> Option<&'a T> {
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Some(&***self)
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}
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}
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impl<T> RawMutPtr<T> for NonZero<*mut T> {
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#[inline]
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unsafe fn as_mut<'a>(&self) -> Option<&'a mut T> {
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Some(&mut ***self)
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}
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}
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