rust/src/test/run-pass/borrowck-borrow-from-expr-block.rs

fn borrow(x: &int, f: fn(x: &int)) {
    f(x)
}

fn test1(x: @~int) {
    // Right now, at least, this induces a copy of the unique pointer:
    do borrow({*x}) { |p|
        let x_a = ptr::addr_of(**x);
        assert (x_a as uint) != (p as uint);
        assert unsafe{*x_a} == *p;
    }
}

fn main() {
    test1(@~22);
}