pub struct Ref<'b, T> where T: 'b + ?Sized { /* fields omitted */ }
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.
impl<'b, T> Ref<'b, T> where T: ?Sized
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fn clone(orig: &Ref<'b, T>) -> Ref<'b, T>
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
.
fn map<U, F>(orig: Ref<'b, T>, f: F) -> Ref<'b, U> where F: FnOnce(&T) -> &U, U: ?Sized
Make 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
.
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)
impl<'b, T, U> CoerceUnsized<Ref<'b, U>> for Ref<'b, T> where T: Unsize<U> + ?Sized,
U: ?Sized
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impl<'b, T> Debug for Ref<'b, T> where T: Debug + ?Sized
[src]
fn fmt(&self, f: &mut Formatter) -> Result<(), Error>
Formats the value using the given formatter.
impl<'b, T> Deref for Ref<'b, T> where T: ?Sized
[src]
type Target = T
The resulting type after dereferencing
fn deref(&self) -> &T
The method called to dereference a value
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/cell/struct.Ref.html