Struct rustc_data_structures::sync::LockGuard 1.0.0[−][src]
pub struct LockGuard<'b, T> where
T: 'b + ?Sized, { /* fields omitted */ }
A wrapper type for a mutably borrowed value from a RefCell<T>
.
See the module-level documentation for more.
Methods
impl<'b, T> RefMut<'b, T> where
T: ?Sized,
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impl<'b, T> RefMut<'b, T> where
T: ?Sized,
pub fn map<U, F>(orig: RefMut<'b, T>, f: F) -> RefMut<'b, U> where
F: FnOnce(&mut T) -> &mut U,
U: ?Sized,
1.8.0[src]
pub fn map<U, F>(orig: RefMut<'b, T>, f: F) -> RefMut<'b, U> where
F: FnOnce(&mut T) -> &mut U,
U: ?Sized,
1.8.0
[src]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
.
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'));
Trait Implementations
impl<'b, T, U> CoerceUnsized<RefMut<'b, U>> for RefMut<'b, T> where
T: Unsize<U> + ?Sized,
U: ?Sized,
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impl<'b, T, U> CoerceUnsized<RefMut<'b, U>> for RefMut<'b, T> where
T: Unsize<U> + ?Sized,
U: ?Sized,
impl<'a, T> Display for RefMut<'a, T> where
T: Display + ?Sized,
1.20.0[src]
impl<'a, T> Display for RefMut<'a, T> where
T: Display + ?Sized,
1.20.0
[src]fn fmt(&self, f: &mut Formatter) -> Result<(), Error>
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fn fmt(&self, f: &mut Formatter) -> Result<(), Error>
Formats the value using the given formatter. Read more
impl<'b, T> DerefMut for RefMut<'b, T> where
T: ?Sized,
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impl<'b, T> DerefMut for RefMut<'b, T> where
T: ?Sized,
ⓘImportant traits for &'a mut Rfn deref_mut(&mut self) -> &mut T
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ⓘImportant traits for &'a mut R
fn deref_mut(&mut self) -> &mut T
Mutably dereferences the value.
impl<'b, T> Deref for RefMut<'b, T> where
T: ?Sized,
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impl<'b, T> Deref for RefMut<'b, T> where
T: ?Sized,
type Target = T
The resulting type after dereferencing.
ⓘImportant traits for &'a mut Rfn deref(&self) -> &T
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ⓘImportant traits for &'a mut R
fn deref(&self) -> &T
Dereferences the value.
impl<'b, T> Debug for RefMut<'b, T> where
T: Debug + ?Sized,
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impl<'b, T> Debug for RefMut<'b, T> where
T: Debug + ?Sized,
fn fmt(&self, f: &mut Formatter) -> Result<(), Error>
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fn fmt(&self, f: &mut Formatter) -> Result<(), Error>
Formats the value using the given formatter. Read more
impl<'a, T> StableDeref for RefMut<'a, T> where
T: ?Sized,
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impl<'a, T> StableDeref for RefMut<'a, T> where
T: ?Sized,