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