1.0.0[−][src]Struct rustc_data_structures::sync::MappedWriteGuard
A wrapper type for a mutably borrowed value from a RefCell<T>
.
See the module-level documentation for more.
Fields
value: &'b mut T
borrow: BorrowRefMut<'b>
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,
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'));
pub fn map_split<U, V, F>(
orig: RefMut<'b, T>,
f: F
) -> (RefMut<'b, U>, RefMut<'b, V>) where
F: FnOnce(&mut T) -> (&mut U, &mut V),
U: ?Sized,
V: ?Sized,
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pub fn map_split<U, V, F>(
orig: RefMut<'b, T>,
f: F
) -> (RefMut<'b, U>, RefMut<'b, V>) where
F: FnOnce(&mut T) -> (&mut U, &mut V),
U: ?Sized,
V: ?Sized,
refcell_map_split
)Split a RefMut
into multiple RefMut
s for different components of the
borrowed data.
The underlying RefCell
will remain mutably borrowed until both
returned RefMut
s 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
#![feature(refcell_map_split)] 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]);
Trait Implementations
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<'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<'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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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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fn deref(&self) -> &T
Dereferences the value.
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,
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,
impl<'a, T> StableDeref for RefMut<'a, T> where
T: ?Sized,
Auto Trait Implementations
Blanket Implementations
impl<T> Erased for T
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impl<T> Erased for T
impl<T> Send for T where
T: ?Sized,
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impl<T> Send for T where
T: ?Sized,
impl<T> Sync for T where
T: ?Sized,
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impl<T> Sync for T where
T: ?Sized,
impl<T> From for T
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impl<T> From for T
impl<T> ToString for T where
T: Display + ?Sized,
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impl<T> ToString for T where
T: Display + ?Sized,
impl<T, U> Into for T where
U: From<T>,
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impl<T, U> Into for T where
U: From<T>,
impl<T, U> TryFrom for T where
T: From<U>,
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impl<T, U> TryFrom for T where
T: From<U>,
type Error = !
try_from
)The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
try_from
)Performs the conversion.
impl<T> Borrow for T where
T: ?Sized,
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impl<T> Borrow for T where
T: ?Sized,
ⓘImportant traits for &'a mut Rfn borrow(&self) -> &T
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fn borrow(&self) -> &T
Immutably borrows from an owned value. Read more
impl<T, U> TryInto for T where
U: TryFrom<T>,
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impl<T, U> TryInto for T where
U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
try_from
)The type returned in the event of a conversion error.
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
try_from
)Performs the conversion.
impl<T> BorrowMut for T where
T: ?Sized,
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impl<T> BorrowMut for T where
T: ?Sized,
ⓘImportant traits for &'a mut Rfn borrow_mut(&mut self) -> &mut T
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fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
impl<T> Any for T where
T: 'static + ?Sized,
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impl<T> Any for T where
T: 'static + ?Sized,
fn get_type_id(&self) -> TypeId
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fn get_type_id(&self) -> TypeId
🔬 This is a nightly-only experimental API. (get_type_id
)
this method will likely be replaced by an associated static
Gets the TypeId
of self
. Read more
impl<E> SpecializationError for E
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impl<E> SpecializationError for E
fn not_found<S, T>(trait_name: &'static str, method_name: &'static str) -> E where
T: ?Sized,
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fn not_found<S, T>(trait_name: &'static str, method_name: &'static str) -> E where
T: ?Sized,
🔬 This is a nightly-only experimental API. (rustc_private
)
this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml
instead?
Create an error for a missing method specialization. Defaults to panicking with type, trait & method names. S
is the encoder/decoder state type, T
is the type being encoded/decoded, and the arguments are the names of the trait and method that should've been overridden. Read more
impl<T> Erased for T
impl<T> Erased for T