Crate ref_portals

Safely use (stack) references outside their original scope.

Example

use ref_portals::rc::Anchor;
 
let x = "Scoped".to_owned();
let anchor = Anchor::new(&x);
let self_owned: Box<dyn Fn() + 'static> = Box::new({
    let portal = anchor.portal();
    move || println!("{}", *portal)
});
 
self_owned(); // Scoped

Note that dropping anchor before self_owned would still cause a panic here.
You can use weak portals to work around this:

use ref_portals::rc::Anchor;
 
let x = "Scoped".to_owned();
let anchor = Anchor::new(&x);
let eternal: &'static dyn Fn() = Box::leak(Box::new({
    let weak_portal = anchor.weak_portal();
    move || println!(
        "{}",
        *weak_portal.upgrade(), // Panics iff the anchor has been dropped.
    )
}));
 
eternal(); // Scoped

Notes

Panic assertions in this documentation use assert_panic.

Modules

• rc
  Single-threaded anchors and portals.
  These don’t implement Send or Sync, but are more efficient for use cases where that’s not needed.
• sync
  Theadsafe anchors and portals.
  These (but not their guards) are various degrees of Send and Sync depending on their type parameter.