mirror of https://github.com/rust-lang/rust
63 lines
1.4 KiB
Rust
63 lines
1.4 KiB
Rust
static static_x: i32 = 1;
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static mut static_x_mut: i32 = 1;
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fn main() {
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let x = 1;
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let mut x_mut = 1;
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{
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// borrow of local
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let _y1 = &mut x; //~ ERROR [E0596]
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let _y2 = &mut x_mut; // No error
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}
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{
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// borrow of static
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let _y1 = &mut static_x; //~ ERROR [E0596]
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unsafe {
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let _y2 = &mut static_x_mut;
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//~^ WARN mutable reference to mutable static is discouraged [static_mut_refs]
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}
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}
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{
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// borrow of deref to box
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let box_x = Box::new(1);
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let mut box_x_mut = Box::new(1);
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let _y1 = &mut *box_x; //~ ERROR [E0596]
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let _y2 = &mut *box_x_mut; // No error
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}
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{
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// borrow of deref to reference
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let ref_x = &x;
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let ref_x_mut = &mut x_mut;
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let _y1 = &mut *ref_x; //~ ERROR [E0596]
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let _y2 = &mut *ref_x_mut; // No error
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}
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{
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// borrow of deref to pointer
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let ptr_x: *const _ = &x;
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let ptr_mut_x: *mut _ = &mut x_mut;
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unsafe {
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let _y1 = &mut *ptr_x; //~ ERROR [E0596]
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let _y2 = &mut *ptr_mut_x; // No error
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}
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}
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{
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// borrowing mutably through an immutable reference
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struct Foo<'a> {
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f: &'a mut i32,
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g: &'a i32,
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};
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let mut foo = Foo { f: &mut x_mut, g: &x };
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let foo_ref = &foo;
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let _y = &mut *foo_ref.f; //~ ERROR [E0596]
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}
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}
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