mirror of https://github.com/rust-lang/rust
46 lines
974 B
Rust
46 lines
974 B
Rust
//@ check-pass
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use std::sync::Mutex;
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struct Foo {
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x: usize
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}
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const fn foo() -> Foo {
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Foo { x: 0 }
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}
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impl Foo {
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const fn bar(&mut self) -> usize {
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self.x = 1;
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self.x
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}
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}
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const fn baz(foo: &mut Foo) -> usize {
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let x = &mut foo.x;
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*x = 2;
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*x
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}
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const fn bazz(foo: &mut Foo) -> usize {
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foo.x = 3;
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foo.x
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}
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// Empty slices get promoted so this passes the static checks.
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// Make sure it also passes the dynamic checks.
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static MUTABLE_REFERENCE_HOLDER: Mutex<&mut [u8]> = Mutex::new(&mut []);
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// This variant with a non-empty slice also seems entirely reasonable.
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static MUTABLE_REFERENCE_HOLDER2: Mutex<&mut [u8]> = unsafe {
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static mut FOO: [u8; 1] = [42]; // a private static that we are sure nobody else will reference
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Mutex::new(&mut *std::ptr::addr_of_mut!(FOO))
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};
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fn main() {
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let _: [(); foo().bar()] = [(); 1];
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let _: [(); baz(&mut foo())] = [(); 2];
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let _: [(); bazz(&mut foo())] = [(); 3];
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}
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