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