46 lines
1.2 KiB
Rust
46 lines
1.2 KiB
Rust
// Copyright 2018 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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use std::{hash, ptr};
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use std::ops::Deref;
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/// A wrapper around reference that compares and hashes like a pointer.
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/// Can be used as a key in sets/maps indexed by pointers to avoid `unsafe`.
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#[derive(Debug)]
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pub struct PtrKey<'a, T: 'a>(pub &'a T);
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impl<'a, T> Clone for PtrKey<'a, T> {
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fn clone(&self) -> Self { *self }
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}
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impl<'a, T> Copy for PtrKey<'a, T> {}
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impl<'a, T> PartialEq for PtrKey<'a, T> {
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fn eq(&self, rhs: &Self) -> bool {
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ptr::eq(self.0, rhs.0)
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}
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}
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impl<'a, T> Eq for PtrKey<'a, T> {}
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impl<'a, T> hash::Hash for PtrKey<'a, T> {
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fn hash<H: hash::Hasher>(&self, hasher: &mut H) {
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(self.0 as *const T).hash(hasher)
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}
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}
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impl<'a, T> Deref for PtrKey<'a, T> {
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type Target = T;
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fn deref(&self) -> &Self::Target {
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self.0
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}
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}
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