1.0.0[−][src]Struct std::cell::Ref
Wraps a borrowed reference to a value in a RefCell box.
A wrapper type for an immutably borrowed value from a RefCell<T>.
See the module-level documentation for more.
Methods
impl<'b, T> Ref<'b, T> where
T: ?Sized, [src]
T: ?Sized,
pub fn clone(orig: &Ref<'b, T>) -> Ref<'b, T>1.15.0[src]
Copies a Ref.
The RefCell is already immutably borrowed, so this cannot fail.
This is an associated function that needs to be used as
Ref::clone(...). A Clone implementation or a method would interfere
with the widespread use of r.borrow().clone() to clone the contents of
a RefCell.
pub fn map<U, F>(orig: Ref<'b, T>, f: F) -> Ref<'b, U> where
F: FnOnce(&T) -> &U,
U: ?Sized, 1.8.0[src]
F: FnOnce(&T) -> &U,
U: ?Sized,
Makes a new Ref for a component of the borrowed data.
The RefCell is already immutably borrowed, so this cannot fail.
This is an associated function that needs to be used as Ref::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, Ref}; let c = RefCell::new((5, 'b')); let b1: Ref<(u32, char)> = c.borrow(); let b2: Ref<u32> = Ref::map(b1, |t| &t.0); assert_eq!(*b2, 5)Run
pub fn map_split<U, V, F>(orig: Ref<'b, T>, f: F) -> (Ref<'b, U>, Ref<'b, V>) where
F: FnOnce(&T) -> (&U, &V),
U: ?Sized,
V: ?Sized, [src]
F: FnOnce(&T) -> (&U, &V),
U: ?Sized,
V: ?Sized,
Splits a Ref into multiple Refs for different components of the
borrowed data.
The RefCell is already immutably borrowed, so this cannot fail.
This is an associated function that needs to be used as
Ref::map_split(...). A method would interfere with methods of the same
name on the contents of a RefCell used through Deref.
Examples
#![feature(refcell_map_split)] use std::cell::{Ref, RefCell}; let cell = RefCell::new([1, 2, 3, 4]); let borrow = cell.borrow(); let (begin, end) = Ref::map_split(borrow, |slice| slice.split_at(2)); assert_eq!(*begin, [1, 2]); assert_eq!(*end, [3, 4]);Run
Trait Implementations
impl<'_, T> Display for Ref<'_, T> where
T: Display + ?Sized, 1.20.0[src]
T: Display + ?Sized,
impl<'b, T, U> CoerceUnsized<Ref<'b, U>> for Ref<'b, T> where
T: Unsize<U> + ?Sized,
U: ?Sized, [src]
T: Unsize<U> + ?Sized,
U: ?Sized,
impl<'_, T> Debug for Ref<'_, T> where
T: Debug + ?Sized, [src]
T: Debug + ?Sized,
impl<'_, T> Deref for Ref<'_, T> where
T: ?Sized, [src]
T: ?Sized,
Auto Trait Implementations
Blanket Implementations
impl<T, U> TryFrom 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(value: U) -> Result<T, <T as TryFrom<U>>::Error>[src]
impl<T> From for T[src]
impl<T, U> TryInto 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> Into for T where
U: From<T>, [src]
U: From<T>,
impl<T> Borrow for T where
T: ?Sized, [src]
T: ?Sized,
impl<T> BorrowMut for T where
T: ?Sized, [src]
T: ?Sized,
ⓘImportant traits for &'_ mut Ifn borrow_mut(&mut self) -> &mut T[src]
impl<T> Any for T where
T: 'static + ?Sized, [src]
T: 'static + ?Sized,
impl<T> ToString for T where
T: Display + ?Sized, [src]
T: Display + ?Sized,