1.0.0[−][src]Struct core::cell::RefMut
A wrapper type for a mutably borrowed value from a RefCell<T>.
See the module-level documentation for more.
Methods
impl<'b, T: ?Sized> RefMut<'b, T>[src]
pub fn map<U: ?Sized, F>(orig: RefMut<'b, T>, f: F) -> RefMut<'b, U> where
F: FnOnce(&mut T) -> &mut U, 1.8.0[src]
F: FnOnce(&mut T) -> &mut U,
Makes a new RefMut for a component of the borrowed data, e.g., an enum
variant.
The RefCell is already mutably borrowed, so this cannot fail.
This is an associated function that needs to be used as
RefMut::map(...). A method would interfere with methods of the same
name on the contents of a RefCell used through Deref.
Examples
use std::cell::{RefCell, RefMut}; let c = RefCell::new((5, 'b')); { let b1: RefMut<(u32, char)> = c.borrow_mut(); let mut b2: RefMut<u32> = RefMut::map(b1, |t| &mut t.0); assert_eq!(*b2, 5); *b2 = 42; } assert_eq!(*c.borrow(), (42, 'b'));Run
pub fn map_split<U: ?Sized, V: ?Sized, F>(
orig: RefMut<'b, T>,
f: F
) -> (RefMut<'b, U>, RefMut<'b, V>) where
F: FnOnce(&mut T) -> (&mut U, &mut V), 1.35.0[src]
orig: RefMut<'b, T>,
f: F
) -> (RefMut<'b, U>, RefMut<'b, V>) where
F: FnOnce(&mut T) -> (&mut U, &mut V),
Splits a RefMut into multiple RefMuts for different components of the
borrowed data.
The underlying RefCell will remain mutably borrowed until both
returned RefMuts go out of scope.
The RefCell is already mutably borrowed, so this cannot fail.
This is an associated function that needs to be used as
RefMut::map_split(...). A method would interfere with methods of the
same name on the contents of a RefCell used through Deref.
Examples
use std::cell::{RefCell, RefMut}; let cell = RefCell::new([1, 2, 3, 4]); let borrow = cell.borrow_mut(); let (mut begin, mut end) = RefMut::map_split(borrow, |slice| slice.split_at_mut(2)); assert_eq!(*begin, [1, 2]); assert_eq!(*end, [3, 4]); begin.copy_from_slice(&[4, 3]); end.copy_from_slice(&[2, 1]);Run
Trait Implementations
impl<T: ?Sized, '_> Deref for RefMut<'_, T>[src]
impl<T: ?Sized, '_> DerefMut for RefMut<'_, T>[src]
impl<'b, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<RefMut<'b, U>> for RefMut<'b, T>[src]
impl<T: ?Sized + Debug, '_> Debug for RefMut<'_, T>[src]
impl<T: ?Sized + Display, '_> Display for RefMut<'_, T>1.20.0[src]
Auto Trait Implementations
Blanket Implementations
impl<T, U> Into<U> for T where
U: From<T>, [src]
U: From<T>,
impl<T> From<T> for T[src]
impl<T, U> TryInto<U> for T where
U: TryFrom<T>, [src]
U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
fn try_into(Self) -> Result<U, <U as TryFrom<T>>::Error>[src]
impl<T, U> TryFrom<U> for T where
U: Into<T>, [src]
U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
fn try_from(U) -> Result<T, <T as TryFrom<U>>::Error>[src]
impl<T> Borrow<T> for T where
T: ?Sized, [src]
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized, [src]
T: ?Sized,
fn borrow_mut(&mut Self) -> &mut T[src]
impl<T> Any for T where
T: 'static + ?Sized, [src]
T: 'static + ?Sized,