mirror of https://github.com/rust-lang/rust
33 lines
829 B
Rust
33 lines
829 B
Rust
fn borrow_mut<T>(x: &mut T) -> &mut T { x }
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fn borrow<T>(x: &T) -> &T { x }
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fn borrow_mut2<T>(_: &mut T, _: &mut T) {}
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fn borrow2<T>(_: &mut T, _: &T) {}
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fn double_mut_borrow<T>(x: &mut Box<T>) {
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let y = borrow_mut(x);
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let z = borrow_mut(x);
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//~^ ERROR cannot borrow `*x` as mutable more than once at a time
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drop((y, z));
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}
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fn double_imm_borrow(x: &mut Box<i32>) {
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let y = borrow(x);
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let z = borrow(x);
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**x += 1;
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//~^ ERROR cannot assign to `**x` because it is borrowed
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drop((y, z));
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}
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fn double_mut_borrow2<T>(x: &mut Box<T>) {
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borrow_mut2(x, x);
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//~^ ERROR cannot borrow `*x` as mutable more than once at a time
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}
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fn double_borrow2<T>(x: &mut Box<T>) {
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borrow2(x, x);
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//~^ ERROR cannot borrow `*x` as mutable because it is also borrowed as immutable
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}
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pub fn main() {}
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