std::cell::RefCell - Rust (original) (raw)
Struct std::cell::RefCell1.0.0 [−] [src]
pub struct RefCell where
T: ?Sized, { /* fields omitted */ }
impl<T> [RefCell](../../std/cell/struct.RefCell.html "struct std::cell::RefCell")<T>[src]
pub const fn [new](#method.new)(value: T) -> [RefCell](../../std/cell/struct.RefCell.html "struct std::cell::RefCell")<T>[src]
Creates a new RefCell containing value.
use std::cell::RefCell;
let c = RefCell::new(5);Run
pub fn [into_inner](#method.into%5Finner)(self) -> T[src]
Consumes the RefCell, returning the wrapped value.
use std::cell::RefCell;
let c = RefCell::new(5);
let five = c.into_inner();Run
pub fn [replace](#method.replace)(&self, t: T) -> T
1.24.0
Replaces the wrapped value with a new one, returning the old value, without deinitializing either one.
This function corresponds to std::mem::replace.
Panics if the value is currently borrowed.
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));Run
`pub fn replace_with(&self, f: F) -> T where
F: FnOnce(&mut T) -> T, `[src]
🔬 This is a nightly-only experimental API. (refcell_replace_swap #43570)
Replaces the wrapped value with a new one computed from f, returning the old value, without deinitializing either one.
This function corresponds to std::mem::replace.
Panics if the value is currently borrowed.
#![feature(refcell_replace_swap)] 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));Run
pub fn [swap](#method.swap)(&self, other: &[RefCell](../../std/cell/struct.RefCell.html "struct std::cell::RefCell")<T>)
1.24.0
Swaps the wrapped value of self with the wrapped value of other, without deinitializing either one.
This function corresponds to std::mem::swap.
Panics if the value in either RefCell is currently borrowed.
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));Run
`impl RefCell where
pub fn [borrow](#method.borrow)(&self) -> [Ref](../../std/cell/struct.Ref.html "struct std::cell::Ref")<T>[src]
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 if the value is currently mutably borrowed. For a non-panicking variant, usetry_borrow.
use std::cell::RefCell;
let c = RefCell::new(5);
let borrowed_five = c.borrow(); let borrowed_five2 = c.borrow();Run
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(); }).join();
assert!(result.is_err());Run
pub fn [try_borrow](#method.try%5Fborrow)(&self) -> [Result](../../std/result/enum.Result.html "enum std::result::Result")<[Ref](../../std/cell/struct.Ref.html "struct std::cell::Ref")<T>, [BorrowError](../../std/cell/struct.BorrowError.html "struct std::cell::BorrowError")>
1.13.0
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.
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()); }Run
pub fn [borrow_mut](#method.borrow%5Fmut)(&self) -> [RefMut](../../std/cell/struct.RefMut.html "struct std::cell::RefMut")<T>[src]
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 if the value is currently borrowed. For a non-panicking variant, usetry_borrow_mut.
use std::cell::RefCell;
let c = RefCell::new(5);
*c.borrow_mut() = 7;
assert_eq!(*c.borrow(), 7);Run
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(); }).join();
assert!(result.is_err());Run
pub fn [try_borrow_mut](#method.try%5Fborrow%5Fmut)(&self) -> [Result](../../std/result/enum.Result.html "enum std::result::Result")<[RefMut](../../std/cell/struct.RefMut.html "struct std::cell::RefMut")<T>, [BorrowMutError](../../std/cell/struct.BorrowMutError.html "struct std::cell::BorrowMutError")>
1.13.0
Mutably borrows the wrapped value, returning an error if the value is currently borrowed.
The borrow lasts until the returned RefMut exits scope. The value cannot be borrowed while this borrow is active.
This is the non-panicking variant of borrow_mut.
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());Run
pub fn [as_ptr](#method.as%5Fptr)(&self) -> [*mut T](../primitive.pointer.html)
1.12.0
Returns a raw pointer to the underlying data in this cell.
use std::cell::RefCell;
let c = RefCell::new(5);
let ptr = c.as_ptr();Run
pub fn [get_mut](#method.get%5Fmut)(&mut self) -> [&mut ](../primitive.reference.html)T
1.11.0
Returns a mutable reference to the underlying data.
This call borrows RefCell mutably (at compile-time) so there is no need for dynamic checks.
However be cautious: this method expects self to be mutable, which is generally not the case when using a RefCell. Take a look at theborrow_mut method instead if self isn't mutable.
Also, please be aware that this method is only for special circumstances and is usually not what you want. In case of doubt, use borrow_mut instead.
use std::cell::RefCell;
let mut c = RefCell::new(5); *c.get_mut() += 1;
assert_eq!(c, RefCell::new(6));Run
`impl Debug for RefCell where
`impl 
for RefCell where
`impl Send for RefCell where
`impl<T, U> CoerceUnsized<RefCell> for RefCell where
T: CoerceUnsized, `[src]
`impl Default for RefCell where
`impl Clone for RefCell where
`impl PartialOrd<RefCell> for RefCell where
T: PartialOrd + ?Sized, `
1.10.0
`impl Ord for RefCell where
1.10.0
`impl Eq for RefCell where
1.2.0
`impl PartialEq<RefCell> for RefCell where
fn [eq](../../std/cmp/trait.PartialEq.html#tymethod.eq)(&self, other: &[RefCell](../../std/cell/struct.RefCell.html "struct std::cell::RefCell")<T>) -> [bool](../primitive.bool.html)[src]
This method tests for self and other values to be equal, and is used by ==. Read more
fn [ne](../../std/cmp/trait.PartialEq.html#method.ne)(&self, other: [&](../primitive.reference.html)Rhs) -> [bool](../primitive.bool.html)[src]
This method tests for !=.
impl<T> [From](../../std/convert/trait.From.html "trait std::convert::From")<T> for [RefCell](../../std/cell/struct.RefCell.html "struct std::cell::RefCell")<T>
1.12.0