Struct rant::RantListHandle
source · [−]pub struct RantListHandle(_);
Expand description
Reference handle for a Rant list
Implementations
Methods from Deref<Target = RefCell<RantList>>
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));
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));
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));
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
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());
}
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
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());
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();
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
This method tests for self
and other
values to be equal, and is used
by ==
. Read more
This method tests for !=
.
Convert from a RantValue
.
Returns true
if the type can be used to represent an optional Rant parameter in native functions; otherwise, false
.
Attempts to convert to a RantValue
.
Auto Trait Implementations
impl !RefUnwindSafe for RantListHandle
impl !Send for RantListHandle
impl !Sync for RantListHandle
impl Unpin for RantListHandle
impl !UnwindSafe for RantListHandle
Blanket Implementations
Mutably borrows from an owned value. Read more