42 lines
1.1 KiB
Rust
42 lines
1.1 KiB
Rust
//@ run-pass
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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;
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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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static mut DATA: *const ArenaSet<Vec<u8>> = std::ptr::null_mut();
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static mut ONCE: Once = Once::new();
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ONCE.call_once(|| {
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//~^ WARN creating a shared reference to mutable static is discouraged [static_mut_refs]
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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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