rust/tests/fail/stacked_borrows/box_exclusive_violation1.rs

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fn demo_mut_advanced_unique(mut our: Box<i32>) -> i32 {
unknown_code_1(&*our);
// This "re-asserts" uniqueness of the reference: After writing, we know
// our tag is at the top of the stack.
*our = 5;
unknown_code_2();
// We know this will return 5
*our
}
// Now comes the evil context
use std::ptr;
static mut LEAK: *mut i32 = ptr::null_mut();
fn unknown_code_1(x: &i32) {
unsafe {
LEAK = x as *const _ as *mut _;
}
}
fn unknown_code_2() {
unsafe {
*LEAK = 7; //~ ERROR: borrow stack
}
}
fn main() {
demo_mut_advanced_unique(Box::new(0));
}