Struct redox::cell::RefCell
[−]
[src]
pub struct RefCell<T> where T: ?Sized {
// some fields omitted
}
A mutable memory location with dynamically checked borrow rules
See the module-level documentation for more.
Methods
impl<T> RefCell<T>
fn new(value: T) -> RefCell<T>
fn into_inner(self) -> T
Consumes the RefCell
, returning the wrapped value.
Examples
use std::cell::RefCell; let c = RefCell::new(5); let five = c.into_inner();
impl<T> RefCell<T> where T: ?Sized
fn borrow_state(&self) -> BorrowState
borrow_state
)Query the current state of this RefCell
The returned value can be dispatched on to determine if a call to
borrow
or borrow_mut
would succeed.
fn borrow(&self) -> Ref<T>
Immutably borrows the wrapped value.
The borrow lasts until the returned Ref
exits scope. Multiple
immutable borrows can be taken out at the same time.
Panics
Panics if the value is currently mutably borrowed.
Examples
use std::cell::RefCell; let c = RefCell::new(5); let borrowed_five = c.borrow(); let borrowed_five2 = c.borrow();
An example of panic:
use std::cell::RefCell; use std::thread; let result = thread::spawn(move || { let c = RefCell::new(5); let m = c.borrow_mut(); let b = c.borrow(); // this causes a panic }).join(); assert!(result.is_err());
fn borrow_mut(&self) -> RefMut<T>
Mutably borrows the wrapped value.
The borrow lasts until the returned RefMut
exits scope. The value
cannot be borrowed while this borrow is active.
Panics
Panics if the value is currently borrowed.
Examples
use std::cell::RefCell; let c = RefCell::new(5); let borrowed_five = c.borrow_mut();
An example of panic:
use std::cell::RefCell; use std::thread; let result = thread::spawn(move || { let c = RefCell::new(5); let m = c.borrow(); let b = c.borrow_mut(); // this causes a panic }).join(); assert!(result.is_err());
unsafe fn as_unsafe_cell(&self) -> &UnsafeCell<T>
as_unsafe_cell
)Returns a reference to the underlying UnsafeCell
.
This can be used to circumvent RefCell
's safety checks.
This function is unsafe
because UnsafeCell
's field is public.