Struct toolbelt::cell::SimpleCell
source · [−]#[repr(transparent)]pub struct SimpleCell<T: ?Sized>(_);
Expand description
Just a wrapper around Rc<RefCell
Implementations
sourceimpl<T> SimpleCell<T>
impl<T> SimpleCell<T>
pub fn new(value: T) -> Self
pub fn replace(&self, value: T) -> T
pub fn try_unwrap(self) -> Result<T, SimpleCell<T>>
pub fn replace_with<F>(&self, f: F) -> T where
F: FnOnce(&mut T) -> T,
pub fn swap(&self, other: &SimpleCell<T>)
pub fn get(&self) -> Ref<'_, T>
pub fn try_get(&self) -> Result<Ref<'_, T>, BorrowError>
pub fn get_mut(&self) -> RefMut<'_, T>
pub fn try_get_mut(&self) -> Result<RefMut<'_, T>, BorrowMutError>
pub fn as_ptr(&self) -> *mut T
pub fn clone(&self) -> Self
sourceimpl<T: Default> SimpleCell<T>
impl<T: Default> SimpleCell<T>
Methods from Deref<Target = RefCell<T>>
1.24.0 · sourcepub fn replace(&self, t: T) -> T
pub fn replace(&self, t: T) -> T
Replaces the wrapped value with a new one, returning the old value, without deinitializing either one.
This function corresponds to std::mem::replace
.
Panics
Panics if the value is currently borrowed.
Examples
use std::cell::RefCell;
let cell = RefCell::new(5);
let old_value = cell.replace(6);
assert_eq!(old_value, 5);
assert_eq!(cell, RefCell::new(6));
1.35.0 · sourcepub fn replace_with<F>(&self, f: F) -> T where
F: for<'_> FnOnce(&mut T) -> T,
pub fn replace_with<F>(&self, f: F) -> T where
F: for<'_> FnOnce(&mut T) -> T,
Replaces the wrapped value with a new one computed from f
, returning
the old value, without deinitializing either one.
Panics
Panics if the value is currently borrowed.
Examples
use std::cell::RefCell;
let cell = RefCell::new(5);
let old_value = cell.replace_with(|&mut old| old + 1);
assert_eq!(old_value, 5);
assert_eq!(cell, RefCell::new(6));
1.24.0 · sourcepub fn swap(&self, other: &RefCell<T>)
pub fn swap(&self, other: &RefCell<T>)
Swaps the wrapped value of self
with the wrapped value of other
,
without deinitializing either one.
This function corresponds to std::mem::swap
.
Panics
Panics if the value in either RefCell
is currently borrowed.
Examples
use std::cell::RefCell;
let c = RefCell::new(5);
let d = RefCell::new(6);
c.swap(&d);
assert_eq!(c, RefCell::new(6));
assert_eq!(d, RefCell::new(5));
1.0.0 · sourcepub fn borrow(&self) -> Ref<'_, T>
pub 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. For a non-panicking variant, use
try_borrow
.
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;
let c = RefCell::new(5);
let m = c.borrow_mut();
let b = c.borrow(); // this causes a panic
1.13.0 · sourcepub fn try_borrow(&self) -> Result<Ref<'_, T>, BorrowError>
pub fn try_borrow(&self) -> Result<Ref<'_, T>, BorrowError>
Immutably borrows the wrapped value, returning an error if the value is currently mutably borrowed.
The borrow lasts until the returned Ref
exits scope. Multiple immutable borrows can be
taken out at the same time.
This is the non-panicking variant of borrow
.
Examples
use std::cell::RefCell;
let c = RefCell::new(5);
{
let m = c.borrow_mut();
assert!(c.try_borrow().is_err());
}
{
let m = c.borrow();
assert!(c.try_borrow().is_ok());
}
1.0.0 · sourcepub fn borrow_mut(&self) -> RefMut<'_, T>
pub fn borrow_mut(&self) -> RefMut<'_, T>
Mutably borrows the wrapped value.
The borrow lasts until the returned RefMut
or all RefMut
s derived
from it exit scope. The value cannot be borrowed while this borrow is
active.
Panics
Panics if the value is currently borrowed. For a non-panicking variant, use
try_borrow_mut
.
Examples
use std::cell::RefCell;
let c = RefCell::new("hello".to_owned());
*c.borrow_mut() = "bonjour".to_owned();
assert_eq!(&*c.borrow(), "bonjour");
An example of panic:
use std::cell::RefCell;
let c = RefCell::new(5);
let m = c.borrow();
let b = c.borrow_mut(); // this causes a panic
1.13.0 · sourcepub fn try_borrow_mut(&self) -> Result<RefMut<'_, T>, BorrowMutError>
pub fn try_borrow_mut(&self) -> Result<RefMut<'_, T>, BorrowMutError>
Mutably borrows the wrapped value, returning an error if the value is currently borrowed.
The borrow lasts until the returned RefMut
or all RefMut
s derived
from it exit scope. The value cannot be borrowed while this borrow is
active.
This is the non-panicking variant of borrow_mut
.
Examples
use std::cell::RefCell;
let c = RefCell::new(5);
{
let m = c.borrow();
assert!(c.try_borrow_mut().is_err());
}
assert!(c.try_borrow_mut().is_ok());
1.12.0 · sourcepub fn as_ptr(&self) -> *mut T
pub fn as_ptr(&self) -> *mut T
Returns a raw pointer to the underlying data in this cell.
Examples
use std::cell::RefCell;
let c = RefCell::new(5);
let ptr = c.as_ptr();
1.37.0 · sourcepub unsafe fn try_borrow_unguarded(&self) -> Result<&T, BorrowError>
pub unsafe fn try_borrow_unguarded(&self) -> Result<&T, BorrowError>
Immutably borrows the wrapped value, returning an error if the value is currently mutably borrowed.
Safety
Unlike RefCell::borrow
, this method is unsafe because it does not
return a Ref
, thus leaving the borrow flag untouched. Mutably
borrowing the RefCell
while the reference returned by this method
is alive is undefined behaviour.
Examples
use std::cell::RefCell;
let c = RefCell::new(5);
{
let m = c.borrow_mut();
assert!(unsafe { c.try_borrow_unguarded() }.is_err());
}
{
let m = c.borrow();
assert!(unsafe { c.try_borrow_unguarded() }.is_ok());
}
Trait Implementations
sourceimpl<T: Debug> Debug for SimpleCell<T>
impl<T: Debug> Debug for SimpleCell<T>
sourceimpl<T: Default> Default for SimpleCell<T>
impl<T: Default> Default for SimpleCell<T>
sourceimpl<T> Deref for SimpleCell<T>
impl<T> Deref for SimpleCell<T>
sourceimpl<T> From<T> for SimpleCell<T>
impl<T> From<T> for SimpleCell<T>
sourceimpl<T: PartialEq + ?Sized> PartialEq<SimpleCell<T>> for SimpleCell<T>
impl<T: PartialEq + ?Sized> PartialEq<SimpleCell<T>> for SimpleCell<T>
impl<T: Eq> Eq for SimpleCell<T>
Auto Trait Implementations
impl<T> !RefUnwindSafe for SimpleCell<T>
impl<T> !Send for SimpleCell<T>
impl<T> !Sync for SimpleCell<T>
impl<T: ?Sized> Unpin for SimpleCell<T>
impl<T> !UnwindSafe for SimpleCell<T>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more