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