rust/src/test/run-pass/borrowck-preserve-box-in-uniq.rs
2012-08-23 11:14:14 -07:00

21 lines
492 B
Rust

// exec-env:RUST_POISON_ON_FREE=1
fn borrow(x: &int, f: fn(x: &int)) {
let before = *x;
f(x);
let after = *x;
assert before == after;
}
fn main() {
let mut x = ~mut @{f: ~3};
do borrow(x.f) |b_x| {
assert *b_x == 3;
assert ptr::addr_of(*x.f) == ptr::addr_of(*b_x);
*x = @{f: ~4};
debug!("ptr::addr_of(*b_x) = %x", ptr::addr_of(*b_x) as uint);
assert *b_x == 3;
assert ptr::addr_of(*x.f) != ptr::addr_of(*b_x);
}
}