This crate provides two wrappers for Rc and Arc weak pointers - ReInitRc
and ReInitArc
, both types provides an API to get a pointer (Rc
or Arc
) from inner weak pointer (upgrade) or re-create the value using the provided function (if inner weak pointer points to a dropped value).
The API is:
impl ReInitRc<T, F: FnMut() -> T> {
fn new(init_fn: F) -> Self { ... }
fn get(&mut self) -> Rc<T> { ... }
}
And same for ReInitArc
but ReInitArc::get
returns Arc<T>
The code:
use re_init_rc::ReInitRc;
struct PrintOnDrop;
impl Drop for PrintOnDrop {
fn drop(&mut self) {
println!("Printing on drop")
}
}
fn main() {
let mut x = ReInitRc::new(|| {
println!("Initializing new PrintOnDrop...");
PrintOnDrop
});
let x1 = x.get(); // Initializing new PrintOnDrop...
let x2 = x.get();
drop(x1);
drop(x2); // Printing on drop
let x3 = x.get(); // Initializing new PrintOnDrop...
// As `x3` is just a `Rc<PrintOnDrop>` we can also clone it
let x4 = x3.clone();
drop(x3);
drop(x4); // Print on drop
}
Outputs:
Initializing new PrintOnDrop...
Printing on drop
Initializing new PrintOnDrop...
Printing on drop