Struct core::cell::RefMut1.0.0[][src]

pub struct RefMut<'b, T: ?Sized + 'b> { /* fields omitted */ }

A wrapper type for a mutably borrowed value from a RefCell<T>.

See the module-level documentation for more.


impl<'b, T: ?Sized> RefMut<'b, T>

Make 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.


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

Trait Implementations

impl<'b, T: ?Sized> Deref for RefMut<'b, T>

The resulting type after dereferencing.

Dereferences the value.

impl<'b, T: ?Sized> DerefMut for RefMut<'b, T>

Mutably dereferences the value.

impl<'b, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<RefMut<'b, U>> for RefMut<'b, T>

impl<'a, T: ?Sized + Display> Display for RefMut<'a, T>

Formats the value using the given formatter. Read more

impl<'b, T: ?Sized + Debug> Debug for RefMut<'b, T>

Formats the value using the given formatter. Read more

Auto Trait Implementations

impl<'b, T> !Send for RefMut<'b, T>

impl<'b, T> !Sync for RefMut<'b, T>