Struct ghost_cell::ghost_cell::GhostToken

pub struct GhostToken<'brand> { /* private fields */ }

A GhostToken<'x> is the key to access the content of any &GhostCell<'x, _> sharing the same brand.

Each GhostToken<'x> is created alongside a unique brand (its lifetime), and each GhostCell<'x, T> is associated to one, and only one, GhostToken at a time via this brand. The entire set of GhostCell<'x, T> associated to a given GhostToken<'x> creates a pool of cells all being accessible solely through the one token they are associated to.

The pool of GhostCell associated to a token need not be homogeneous, each may own a value of a different type.

Implementations

impl<'brand> GhostToken<'brand>

pub fn new<R, F>(fun: F) -> Rwhere
    for<'new_brand> F: FnOnce(GhostToken<'new_brand>) -> R,

Creates a fresh token to which GhostCells can be tied to later.

Due to the use of a lifetime, the GhostCells tied to a given token can only live within the confines of the invocation of the fun closure.

Example

use ghost_cell::{GhostToken, GhostCell};

let n = 12;

let value = GhostToken::new(|mut token| {
    let cell = GhostCell::new(42);

    let vec: Vec<_> = (0..n).map(|_| &cell).collect();

    *vec[n / 2].borrow_mut(&mut token) = 33;

    *cell.borrow(&token)
});

assert_eq!(33, value);

Trait Implementations

impl<'brand> Send for GhostToken<'brand>

A GhostToken is stateless, therefore it can safely be passed across threads.

impl<'brand> Sync for GhostToken<'brand>

A GhostToken is stateless, therefore it can safely be accessed from different threads.