If you want that, you'll need to use a custom pointer type instead of ~. You
can use ~ internally, and implement Deref/DerefMut to do the desired capturing.
pub struct Ptr<T> {
value: ~T // assuming 0.10 here, master would be Box<T>
}
impl<T> Ptr<T> {
pub fn new(val: T) -> Ptr<T> {
Ptr { value: ~val }
}
}
impl<T> Deref<T> for Ptr<T> {
fn deref<'a>(&'a self) -> &'a T {
// do any capturing of the dereference here
&*self.value
}
}
impl<T> DerefMut<T> for Ptr<T> {
fn deref_mut<'a>(&'a mut self) -> &'a mut T {
// do any capturing of the mutable dereference here
&mut *self.value
}
}
fn main() {
let x = Ptr::new(3i);
println!("x: {}", *x);
}
-Kevin
On May 13, 2014, at 9:16 PM, Noah Watkins <jayh...@cs.ucsc.edu> wrote:
> On Tue, May 13, 2014 at 2:19 PM, Alex Crichton <a...@crichton.co> wrote:
>> The ~int type has since moved to Box<int>, which will one day be a
>> library type with Deref implemented on it (currently it is implemented
>> by the compiler).
>
> Thanks for the note. I'm using a slightly older version that doesn't
> have Box<T>, but it sounds like ~ is also implemented with the
> compiler. I was actually looking into this because I was interested in
> intercepting the deref (as well as allocate/free) for some distributed
> shared-memory experiments. Some of the safety checks rust performs
> simplifies the coherency requirements needed of the storage layer
> (e.g. expensive locking).
>
> -Noah
>
>>
>> On Mon, May 12, 2014 at 11:50 AM, Noah Watkins <jayh...@cs.ucsc.edu> wrote:
>>> I am trying to capture the reference to type `~int` with the following
>>> code. I can change it to apply to bare `int` and it works fine.
>>>
>>> #[lang="deref"]
>>> pub trait Deref<Result> {
>>> fn deref<'a>(&'a self) -> &'a Result;
>>> }
>>>
>>> impl Deref<~int> for ~int {
>>> fn deref<'a>(&'a self) -> &'a ~int {
>>> println!("deref caught");
>>> self
>>> }
>>> }
>>>
>>> fn main() {
>>> let x: ~int = 3;
>>> *x
>>> }
>>>
>>> Thanks,
>>> Noah
>>> _______________________________________________
>>> Rust-dev mailing list
>>> Rust-dev@mozilla.org
>>> https://mail.mozilla.org/listinfo/rust-dev
> _______________________________________________
> Rust-dev mailing list
> Rust-dev@mozilla.org
> https://mail.mozilla.org/listinfo/rust-dev
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