mirror of https://github.com/rust-lang/rust
61 lines
1.1 KiB
Rust
61 lines
1.1 KiB
Rust
// Test how overloaded deref interacts with borrows when DerefMut
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// is implemented.
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use std::ops::{Deref, DerefMut};
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struct Own<T> {
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value: *mut T
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}
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impl<T> Deref for Own<T> {
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type Target = T;
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fn deref<'a>(&'a self) -> &'a T {
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unsafe { &*self.value }
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}
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}
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impl<T> DerefMut for Own<T> {
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fn deref_mut<'a>(&'a mut self) -> &'a mut T {
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unsafe { &mut *self.value }
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}
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}
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fn deref_imm(x: Own<isize>) {
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let __isize = &*x;
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}
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fn deref_mut1(x: Own<isize>) {
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let __isize = &mut *x; //~ ERROR cannot borrow
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}
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fn deref_mut2(mut x: Own<isize>) {
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let __isize = &mut *x;
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}
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fn deref_extend<'a>(x: &'a Own<isize>) -> &'a isize {
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&**x
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}
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fn deref_extend_mut1<'a>(x: &'a Own<isize>) -> &'a mut isize {
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&mut **x //~ ERROR cannot borrow
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}
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fn deref_extend_mut2<'a>(x: &'a mut Own<isize>) -> &'a mut isize {
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&mut **x
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}
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fn assign1<'a>(x: Own<isize>) {
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*x = 3; //~ ERROR cannot borrow
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}
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fn assign2<'a>(x: &'a Own<isize>) {
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**x = 3; //~ ERROR cannot borrow
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}
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fn assign3<'a>(x: &'a mut Own<isize>) {
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**x = 3;
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}
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pub fn main() {}
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