30 lines
975 B
Rust
30 lines
975 B
Rust
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use std::cell::*;
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// not ok, because this would create a silent constant with interior mutability.
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// the rules could be relaxed in the future
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static FOO: Wrap<*mut u32> = Wrap(Cell::new(42).as_ptr());
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//~^ ERROR cannot borrow a constant which may contain interior mutability
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static FOO3: Wrap<Cell<u32>> = Wrap(Cell::new(42));
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// ok
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static FOO4: Wrap<*mut u32> = Wrap(FOO3.0.as_ptr());
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// not ok, because the `as_ptr` call takes a reference to a type with interior mutability
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// which is not allowed in constants
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const FOO2: *mut u32 = Cell::new(42).as_ptr();
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//~^ ERROR cannot borrow a constant which may contain interior mutability
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struct IMSafeTrustMe(UnsafeCell<u32>);
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unsafe impl Send for IMSafeTrustMe {}
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unsafe impl Sync for IMSafeTrustMe {}
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static BAR: IMSafeTrustMe = IMSafeTrustMe(UnsafeCell::new(5));
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struct Wrap<T>(T);
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unsafe impl<T> Send for Wrap<T> {}
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unsafe impl<T> Sync for Wrap<T> {}
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static BAR_PTR: Wrap<*mut u32> = Wrap(BAR.0.get());
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fn main() {}
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