37 lines
808 B
Rust
37 lines
808 B
Rust
// Check that we properly record borrows when we are doing an
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// overloaded, autoderef of a value obtained via an overloaded index
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// operator. The accounting of the all the implicit things going on
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// here is rather subtle. Issue #20232.
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use std::ops::{Deref, Index};
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struct MyVec<T> { x: T }
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impl<T> Index<usize> for MyVec<T> {
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type Output = T;
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fn index(&self, _: usize) -> &T {
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&self.x
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}
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}
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struct MyPtr<T> { x: T }
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impl<T> Deref for MyPtr<T> {
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type Target = T;
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fn deref(&self) -> &T {
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&self.x
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}
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}
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struct Foo { f: usize }
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fn main() {
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let mut v = MyVec { x: MyPtr { x: Foo { f: 22 } } };
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let i = &v[0].f;
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v = MyVec { x: MyPtr { x: Foo { f: 23 } } };
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//~^ ERROR cannot assign to `v` because it is borrowed
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read(*i);
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}
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fn read(_: usize) { }
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