pub struct Ref<'a, T>where
T: 'static + ?Sized,{ /* private fields */ }
Expand description
A wrapper type for an immutably borrowed value from a GcCell<T>
.
Implementations
sourceimpl<'a, T> GcCellRef<'a, T>where
T: ?Sized,
impl<'a, T> GcCellRef<'a, T>where
T: ?Sized,
sourcepub fn clone(orig: &GcCellRef<'a, T>) -> GcCellRef<'a, T>
pub fn clone(orig: &GcCellRef<'a, T>) -> GcCellRef<'a, T>
Copies a GcCellRef
.
The GcCell
is already immutably borrowed, so this cannot fail.
This is an associated function that needs to be used as
GcCellRef::clone(...)
. A Clone
implementation or a method
would interfere with the use of c.borrow().clone()
to clone
the contents of a GcCell
.
sourcepub fn map<U, F>(orig: GcCellRef<'a, T>, f: F) -> GcCellRef<'a, U>where
F: FnOnce(&T) -> &U,
U: ?Sized,
pub fn map<U, F>(orig: GcCellRef<'a, T>, f: F) -> GcCellRef<'a, U>where
F: FnOnce(&T) -> &U,
U: ?Sized,
Makes a new GcCellRef
from a component of the borrowed data.
The GcCell
is already immutably borrowed, so this cannot fail.
This is an associated function that needs to be used as GcCellRef::map(...)
.
A method would interfere with methods of the same name on the contents
of a GcCellRef
used through Deref
.
Examples
use gc::{GcCell, GcCellRef};
let c = GcCell::new((5, 'b'));
let b1: GcCellRef<(u32, char)> = c.borrow();
let b2: GcCellRef<u32> = GcCellRef::map(b1, |t| &t.0);
//assert_eq!(b2, 5);
sourcepub fn map_split<U, V, F>(
orig: GcCellRef<'a, T>,
f: F
) -> (GcCellRef<'a, U>, GcCellRef<'a, V>)where
F: FnOnce(&T) -> (&U, &V),
U: ?Sized,
V: ?Sized,
pub fn map_split<U, V, F>(
orig: GcCellRef<'a, T>,
f: F
) -> (GcCellRef<'a, U>, GcCellRef<'a, V>)where
F: FnOnce(&T) -> (&U, &V),
U: ?Sized,
V: ?Sized,
Splits a GcCellRef
into multiple GcCellRef
s for different components of the borrowed data.
The GcCell
is already immutably borrowed, so this cannot fail.
This is an associated function that needs to be used as GcCellRef::map_split(…).
A method would interfere with methods of the same name on the contents of a GcCellRef
used through Deref
.
Examples
use gc::{GcCell, GcCellRef};
let cell = GcCell::new((1, 'c'));
let borrow = cell.borrow();
let (first, second) = GcCellRef::map_split(borrow, |x| (&x.0, &x.1));
assert_eq!(*first, 1);
assert_eq!(*second, 'c');