50 lines
1.5 KiB
Rust
50 lines
1.5 KiB
Rust
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// Copyright 2017 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::ops::Deref;
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struct ArenaSet<U: Deref, V=<U as Deref>::Target>(U, &'static V)
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where V: 'static + ?Sized;
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static Z: [u8; 4] = [1,2,3,4];
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fn arena() -> &'static ArenaSet<Vec<u8>> {
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fn __static_ref_initialize() -> ArenaSet<Vec<u8>> {
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ArenaSet(vec![], &Z)
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}
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unsafe {
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use std::sync::{Once, ONCE_INIT};
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fn require_sync<T: Sync>(_: &T) { }
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unsafe fn __stability() -> &'static ArenaSet<Vec<u8>> {
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use std::mem::transmute;
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use std::boxed::Box;
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static mut DATA: *const ArenaSet<Vec<u8>> = 0 as *const ArenaSet<Vec<u8>>;
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static mut ONCE: Once = ONCE_INIT;
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ONCE.call_once(|| {
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DATA = transmute
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::<Box<ArenaSet<Vec<u8>>>, *const ArenaSet<Vec<u8>>>
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(Box::new(__static_ref_initialize()));
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});
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&*DATA
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}
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let static_ref = __stability();
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require_sync(static_ref);
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static_ref
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}
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}
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fn main() {
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let &ArenaSet(ref u, v) = arena();
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assert!(u.is_empty());
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assert_eq!(v, Z);
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}
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