rust/tests/ui/borrowck/borrowck-box-sensitivity.rs

// Test that `Box<T>` is treated specially by borrow checking. This is the case
// because NLL reverted the deicision in rust-lang/rfcs#130.

//@ run-pass

struct A {
    x: Box<isize>,
    y: isize,
}

struct B {
    x: Box<isize>,
    y: Box<isize>,
}

struct C {
    x: Box<A>,
    y: isize,
}

struct D {
    x: Box<A>,
    y: Box<isize>,
}

fn copy_after_move() {
    let a: Box<_> = Box::new(A { x: Box::new(0), y: 1 });
    let _x = a.x;
    let _y = a.y;
}

fn move_after_move() {
    let a: Box<_> = Box::new(B { x: Box::new(0), y: Box::new(1) });
    let _x = a.x;
    let _y = a.y;
}

fn borrow_after_move() {
    let a: Box<_> = Box::new(A { x: Box::new(0), y: 1 });
    let _x = a.x;
    let _y = &a.y;
}

fn move_after_borrow() {
    let a: Box<_> = Box::new(B { x: Box::new(0), y: Box::new(1) });
    let _x = &a.x;
    let _y = a.y;
    use_imm(_x);
}
fn copy_after_mut_borrow() {
    let mut a: Box<_> = Box::new(A { x: Box::new(0), y: 1 });
    let _x = &mut a.x;
    let _y = a.y;
    use_mut(_x);
}
fn move_after_mut_borrow() {
    let mut a: Box<_> = Box::new(B { x: Box::new(0), y: Box::new(1) });
    let _x = &mut a.x;
    let _y = a.y;
    use_mut(_x);
}
fn borrow_after_mut_borrow() {
    let mut a: Box<_> = Box::new(A { x: Box::new(0), y: 1 });
    let _x = &mut a.x;
    let _y = &a.y;
    use_mut(_x);
}
fn mut_borrow_after_borrow() {
    let mut a: Box<_> = Box::new(A { x: Box::new(0), y: 1 });
    let _x = &a.x;
    let _y = &mut a.y;
    use_imm(_x);
}
fn copy_after_move_nested() {
    let a: Box<_> = Box::new(C { x: Box::new(A { x: Box::new(0), y: 1 }), y: 2 });
    let _x = a.x.x;
    let _y = a.y;
}

fn move_after_move_nested() {
    let a: Box<_> = Box::new(D { x: Box::new(A { x: Box::new(0), y: 1 }), y: Box::new(2) });
    let _x = a.x.x;
    let _y = a.y;
}

fn borrow_after_move_nested() {
    let a: Box<_> = Box::new(C { x: Box::new(A { x: Box::new(0), y: 1 }), y: 2 });
    let _x = a.x.x;
    let _y = &a.y;
}

fn move_after_borrow_nested() {
    let a: Box<_> = Box::new(D { x: Box::new(A { x: Box::new(0), y: 1 }), y: Box::new(2) });
    let _x = &a.x.x;
    let _y = a.y;
    use_imm(_x);
}
fn copy_after_mut_borrow_nested() {
    let mut a: Box<_> = Box::new(C { x: Box::new(A { x: Box::new(0), y: 1 }), y: 2 });
    let _x = &mut a.x.x;
    let _y = a.y;
    use_mut(_x);
}
fn move_after_mut_borrow_nested() {
    let mut a: Box<_> = Box::new(D { x: Box::new(A { x: Box::new(0), y: 1 }), y: Box::new(2) });
    let _x = &mut a.x.x;
    let _y = a.y;
    use_mut(_x);
}
fn borrow_after_mut_borrow_nested() {
    let mut a: Box<_> = Box::new(C { x: Box::new(A { x: Box::new(0), y: 1 }), y: 2 });
    let _x = &mut a.x.x;
    let _y = &a.y;
    use_mut(_x);
}
fn mut_borrow_after_borrow_nested() {
    let mut a: Box<_> = Box::new(C { x: Box::new(A { x: Box::new(0), y: 1 }), y: 2 });
    let _x = &a.x.x;
    let _y = &mut a.y;
    use_imm(_x);
}

fn main() {
    copy_after_move();
    move_after_move();
    borrow_after_move();

    move_after_borrow();

    copy_after_mut_borrow();
    move_after_mut_borrow();
    borrow_after_mut_borrow();
    mut_borrow_after_borrow();

    copy_after_move_nested();
    move_after_move_nested();
    borrow_after_move_nested();

    move_after_borrow_nested();

    copy_after_mut_borrow_nested();
    move_after_mut_borrow_nested();
    borrow_after_mut_borrow_nested();
    mut_borrow_after_borrow_nested();
}

fn use_mut<T>(_: &mut T) { }
fn use_imm<T>(_: &T) { }