Struct jrsonnet_gc::GcCellRef

pub struct GcCellRef<'a, T: ?Sized + 'static> { /* fields omitted */ }

A wrapper type for an immutably borrowed value from a GcCell<T>.

Implementations

impl<'a, T: ?Sized> 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.

pub fn map<U, F>(orig: Self, f: F) -> GcCellRef<'a, U> where
    U: ?Sized,
    F: FnOnce(&T) -> &U, 

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 jrsonnet_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);

pub fn map_split<U, V, F>(
    orig: Self,
    f: F
) -> (GcCellRef<'a, U>, GcCellRef<'a, V>) where
    U: ?Sized,
    V: ?Sized,
    F: FnOnce(&T) -> (&U, &V), 

Splits a GcCellRef into multiple GcCellRefs 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 jrsonnet_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');

Trait Implementations

impl<'a, T: ?Sized + Debug> Debug for GcCellRef<'a, T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a, T: ?Sized> Deref for GcCellRef<'a, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<'a, T: ?Sized + Display> Display for GcCellRef<'a, T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a, T: ?Sized> Drop for GcCellRef<'a, T>

fn drop(&mut self)

Executes the destructor for this type.