rust/tests/ui/borrowck/borrowck-issue-14498.rs
2023-01-11 09:32:08 +00:00

111 lines
2.7 KiB
Rust

// This tests that we can't modify Box<&mut T> contents while they
// are borrowed (#14498).
//
// Also includes tests of the errors reported when the Box in question
// is immutable (#14270).
struct A { a: isize }
struct B<'a> { a: Box<&'a mut isize> }
fn indirect_write_to_imm_box() {
let mut x: isize = 1;
let y: Box<_> = Box::new(&mut x);
let p = &y;
***p = 2; //~ ERROR cannot assign to `***p`
drop(p);
}
fn borrow_in_var_from_var() {
let mut x: isize = 1;
let mut y: Box<_> = Box::new(&mut x);
let p = &y;
let q = &***p;
**y = 2; //~ ERROR cannot assign to `**y` because it is borrowed
drop(p);
drop(q);
}
fn borrow_in_var_from_var_via_imm_box() {
let mut x: isize = 1;
let y: Box<_> = Box::new(&mut x);
let p = &y;
let q = &***p;
**y = 2; //~ ERROR cannot assign to `**y` because it is borrowed
drop(p);
drop(q);
}
fn borrow_in_var_from_field() {
let mut x = A { a: 1 };
let mut y: Box<_> = Box::new(&mut x.a);
let p = &y;
let q = &***p;
**y = 2; //~ ERROR cannot assign to `**y` because it is borrowed
drop(p);
drop(q);
}
fn borrow_in_var_from_field_via_imm_box() {
let mut x = A { a: 1 };
let y: Box<_> = Box::new(&mut x.a);
let p = &y;
let q = &***p;
**y = 2; //~ ERROR cannot assign to `**y` because it is borrowed
drop(p);
drop(q);
}
fn borrow_in_field_from_var() {
let mut x: isize = 1;
let mut y = B { a: Box::new(&mut x) };
let p = &y.a;
let q = &***p;
**y.a = 2; //~ ERROR cannot assign to `**y.a` because it is borrowed
drop(p);
drop(q);
}
fn borrow_in_field_from_var_via_imm_box() {
let mut x: isize = 1;
let y = B { a: Box::new(&mut x) };
let p = &y.a;
let q = &***p;
**y.a = 2; //~ ERROR cannot assign to `**y.a` because it is borrowed
drop(p);
drop(q);
}
fn borrow_in_field_from_field() {
let mut x = A { a: 1 };
let mut y = B { a: Box::new(&mut x.a) };
let p = &y.a;
let q = &***p;
**y.a = 2; //~ ERROR cannot assign to `**y.a` because it is borrowed
drop(p);
drop(q);
}
fn borrow_in_field_from_field_via_imm_box() {
let mut x = A { a: 1 };
let y = B { a: Box::new(&mut x.a) };
let p = &y.a;
let q = &***p;
**y.a = 2; //~ ERROR cannot assign to `**y.a` because it is borrowed
drop(p);
drop(q);
}
fn main() {
indirect_write_to_imm_box();
borrow_in_var_from_var();
borrow_in_var_from_var_via_imm_box();
borrow_in_var_from_field();
borrow_in_var_from_field_via_imm_box();
borrow_in_field_from_var();
borrow_in_field_from_var_via_imm_box();
borrow_in_field_from_field();
borrow_in_field_from_field_via_imm_box();
}