Struct Pooled 

pub struct Pooled<M: Manager> { /* private fields */ }

Available on crate feature std only.

A borrowed resource that returns itself to the pool when dropped.

Obtained from Pool::get and Pool::get_timeout. A Pooled<M> deref-coerces to the underlying resource, so it can be used anywhere a &M::Resource or &mut M::Resource is expected. When the guard goes out of scope the resource is recycled (via Manager::recycle) and returned to the idle set — there is no release call to remember, and no way to leak a resource by forgetting one.

If recycling fails, or the pool has been closed, the resource is dropped instead of pooled and its slot is freed for a replacement.

The guard is Send whenever the resource is, so it may be held across .await points in async code.

Examples

use pool_mod::{Manager, Pool};
use std::convert::Infallible;

struct Counters;
impl Manager for Counters {
    type Resource = u64;
    type Error = Infallible;
    fn create(&self) -> Result<u64, Infallible> { Ok(0) }
    fn recycle(&self, _r: &mut u64) -> Result<(), Infallible> { Ok(()) }
}

let pool = Pool::builder(Counters).max_size(2).build()
    .expect("configuration is valid");
{
    let mut n = pool.get().expect("a resource is available");
    *n += 1; // DerefMut to the pooled u64
    assert_eq!(*n, 1);
} // `n` is recycled and returned to the pool here
assert_eq!(pool.status().idle, 1);

Trait Implementations

impl<M: Manager> Deref for Pooled<M>

type Target = <M as Manager>::Resource

The resulting type after dereferencing.

fn deref(&self) -> &M::Resource

Dereferences the value.

impl<M: Manager> DerefMut for Pooled<M>

fn deref_mut(&mut self) -> &mut M::Resource

Mutably dereferences the value.

impl<M: Manager> Drop for Pooled<M>

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.