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.
13 use ops::{CoerceUnsized, DispatchFromDyn};
15 /// A wrapper type for raw pointers and integers that will never be
16 /// NULL or 0 that might allow certain optimizations.
17 #[rustc_layout_scalar_valid_range_start(1)]
18 #[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
20 pub(crate) struct NonZero<T>(pub(crate) T);
22 impl<T: CoerceUnsized<U>, U> CoerceUnsized<NonZero<U>> for NonZero<T> {}
24 impl<T: DispatchFromDyn<U>, U> DispatchFromDyn<NonZero<U>> for NonZero<T> {}