Struct LoanCell

pub struct LoanCell<T: ?Sized>(/* private fields */);

A cell that allows lending a reference to a value for a limited scope.

See the module-level documentation for more information.

Implementations

impl<T: ?Sized> LoanCell<T>

pub const fn new() -> Self

Creates a LoanCell with no loaned data.

pub fn lend<R>(&self, value: &T, f: impl FnOnce() -> R) -> R

Lends value for the lifetime of f. f or any function it calls can access the loaned value via LoanCell::borrow.

If a value is already lent, it is replaced with value for the duration of f and restored afterwards.

pub fn is_lent(&self) -> bool

Returns true if a value is currently lent.

pub fn borrow<R>(&self, f: impl FnOnce(Option<&T>) -> R) -> R

Borrows the lent value for the duration of f. If no value is currently lent, f is called with None.

Trait Implementations

impl<T: Default + ?Sized> Default for LoanCell<T>

fn default() -> LoanCell<T>

Returns the “default value” for a type.

impl<T: RefUnwindSafe + ?Sized> RefUnwindSafe for LoanCell<T>

impl<T: RefUnwindSafe + ?Sized> UnwindSafe for LoanCell<T>