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|
pub struct Foo {
x: u32
}
pub struct Bar(u32);
pub enum Baz {
X(u32)
}
union U {
a: u8,
b: u64,
}
impl Foo {
fn x(&mut self) -> &mut u32 { &mut self.x }
}
impl Bar {
fn x(&mut self) -> &mut u32 { &mut self.0 }
}
impl Baz {
fn x(&mut self) -> &mut u32 {
match *self {
Baz::X(ref mut value) => value
}
}
}
fn main() {
// Local and field from struct
{
let mut f = Foo { x: 22 };
let x = f.x();
f.x; //~ ERROR cannot use `f.x` because it was mutably borrowed
drop(x);
}
// Local and field from tuple-struct
{
let mut g = Bar(22);
let x = g.x();
g.0; //~ ERROR cannot use `g.0` because it was mutably borrowed
drop(x);
}
// Local and field from tuple
{
let mut h = (22, 23);
let x = &mut h.0;
h.0; //~ ERROR cannot use `h.0` because it was mutably borrowed
drop(x);
}
// Local and field from enum
{
let mut e = Baz::X(2);
let x = e.x();
match e {
Baz::X(value) => value //~ ERROR cannot use `e.0` because it was mutably borrowed
};
drop(x);
}
// Local and field from union
unsafe {
let mut u = U { b: 0 };
let x = &mut u.a;
u.a; //~ ERROR cannot use `u.a` because it was mutably borrowed
drop(x);
}
// Deref and field from struct
{
let mut f = Box::new(Foo { x: 22 });
let x = f.x();
f.x; //~ ERROR cannot use `f.x` because it was mutably borrowed
drop(x);
}
// Deref and field from tuple-struct
{
let mut g = Box::new(Bar(22));
let x = g.x();
g.0; //~ ERROR cannot use `g.0` because it was mutably borrowed
drop(x);
}
// Deref and field from tuple
{
let mut h = Box::new((22, 23));
let x = &mut h.0;
h.0; //~ ERROR cannot use `h.0` because it was mutably borrowed
drop(x);
}
// Deref and field from enum
{
let mut e = Box::new(Baz::X(3));
let x = e.x();
match *e {
Baz::X(value) => value
//~^ ERROR cannot use `e.0` because it was mutably borrowed
};
drop(x);
}
// Deref and field from union
unsafe {
let mut u = Box::new(U { b: 0 });
let x = &mut u.a;
u.a; //~ ERROR cannot use `u.a` because it was mutably borrowed
drop(x);
}
// Constant index
{
let mut v = &[1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
let x = &mut v;
match v {
&[x, _, .., _, _] => println!("{}", x),
//~^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
match v {
&[_, x, .., _, _] => println!("{}", x),
//~^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
match v {
&[_, _, .., x, _] => println!("{}", x),
//~^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
match v {
&[_, _, .., _, x] => println!("{}", x),
//~^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
drop(x);
}
// Subslices
{
let mut v = &[1, 2, 3, 4, 5];
let x = &mut v;
match v {
&[x @ ..] => println!("{:?}", x),
//~^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
match v {
&[_, x @ ..] => println!("{:?}", x),
//~^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
match v {
&[x @ .., _] => println!("{:?}", x),
//~^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
match v {
&[_, x @ .., _] => println!("{:?}", x),
//~^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
drop(x);
}
// Downcasted field
{
enum E<X> { A(X), B { x: X } }
let mut e = E::A(3);
let x = &mut e;
match e {
//~^ ERROR cannot use `e` because it was mutably borrowed
E::A(ref ax) =>
//~^ ERROR cannot borrow `e.0` as immutable because it is also borrowed as mutable
println!("e.ax: {:?}", ax),
E::B { x: ref bx } =>
//~^ ERROR cannot borrow `e.x` as immutable because it is also borrowed as mutable
println!("e.bx: {:?}", bx),
}
drop(x);
}
// Field in field
{
struct F { x: u32, y: u32 };
struct S { x: F, y: (u32, u32), };
let mut s = S { x: F { x: 1, y: 2}, y: (999, 998) };
let x = &mut s;
match s {
S { y: (ref y0, _), .. } =>
//~^ ERROR cannot borrow `s.y.0` as immutable because it is also borrowed as mutable
println!("y0: {:?}", y0),
_ => panic!("other case"),
}
match s {
S { x: F { y: ref x0, .. }, .. } =>
//~^ ERROR cannot borrow `s.x.y` as immutable because it is also borrowed as mutable
println!("x0: {:?}", x0),
_ => panic!("other case"),
}
drop(x);
}
// Field of ref
{
struct Block<'a> {
current: &'a u8,
unrelated: &'a u8,
};
fn bump<'a>(mut block: &mut Block<'a>) {
let x = &mut block;
let p: &'a u8 = &*block.current;
//~^ ERROR cannot borrow `*block.current` as immutable because it is also borrowed as mutable
// See issue rust#38899
drop(x);
}
}
// Field of ptr
{
struct Block2 {
current: *const u8,
unrelated: *const u8,
}
unsafe fn bump2(mut block: *mut Block2) {
let x = &mut block;
let p : *const u8 = &*(*block).current;
//~^ ERROR cannot borrow `*block.current` as immutable because it is also borrowed as mutable
// See issue rust#38899
drop(x);
}
}
// Field of index
{
struct F {x: u32, y: u32};
let mut v = &[F{x: 1, y: 2}, F{x: 3, y: 4}];
let x = &mut v;
v[0].y;
//~^ ERROR cannot use `v[_].y` because it was mutably borrowed
//~| ERROR cannot use `*v` because it was mutably borrowed
drop(x);
}
// Field of constant index
{
struct F {x: u32, y: u32};
let mut v = &[F{x: 1, y: 2}, F{x: 3, y: 4}];
let x = &mut v;
match v {
&[_, F {x: ref xf, ..}] => println!("{}", xf),
//~^ ERROR cannot borrow `v[..].x` as immutable because it is also borrowed as mutable
_ => panic!("other case")
}
drop(x);
}
// Field from upvar
{
let mut x = 0;
|| {
let y = &mut x;
&mut x; //~ ERROR cannot borrow `x` as mutable more than once at a time
*y = 1;
};
}
// Field from upvar nested
{
let mut x = 0;
|| {
|| { //~ ERROR captured variable cannot escape `FnMut` closure body
let y = &mut x;
&mut x; //~ ERROR cannot borrow `x` as mutable more than once at a time
*y = 1;
drop(y);
}
};
}
{
fn foo(x: Vec<i32>) {
let c = || {
drop(x);
drop(x); //~ ERROR use of moved value: `x`
};
c();
}
}
}
|
