Struct jrsonnet_gc::Gc

pub struct Gc<T: Trace + ?Sized + 'static> { /* fields omitted */ }

A garbage-collected pointer type over an immutable value.

See the module level documentation for more details.

Implementations

impl<T: Trace> Gc<T>

pub fn new(value: T) -> Self

Constructs a new Gc<T> with the given value.

Collection

This method could trigger a garbage collection.

Examples

use jrsonnet_gc::Gc;

let five = Gc::new(5);
assert_eq!(*five, 5);

impl<T: Trace + ?Sized> Gc<T>

pub fn ptr_eq(this: &Gc<T>, other: &Gc<T>) -> bool

Returns true if the two Gcs point to the same allocation.

impl<T: Trace + ?Sized> Gc<T>

pub fn into_raw(this: Self) -> *const T

Consumes the Gc, returning the wrapped pointer.

To avoid a memory leak, the pointer must be converted back into a Gc using Gc::from_raw.

Examples

use jrsonnet_gc::Gc;

let x = Gc::new(22);
let x_ptr = Gc::into_raw(x);
assert_eq!(unsafe { *x_ptr }, 22);

pub unsafe fn from_raw(ptr: *const T) -> Self

Constructs an Gc from a raw pointer.

The raw pointer must have been previously returned by a call to a Gc::into_raw.

This function is unsafe because improper use may lead to memory problems. For example, a use-after-free will occur if the function is called twice on the same raw pointer.

Examples

use jrsonnet_gc::Gc;

let x = Gc::new(22);
let x_ptr = Gc::into_raw(x);

unsafe {
    // Convert back to an `Gc` to prevent leak.
    let x = Gc::from_raw(x_ptr);
    assert_eq!(*x, 22);

    // Further calls to `Gc::from_raw(x_ptr)` would be memory unsafe.
}

// The memory can be freed at any time after `x` went out of scope above
// (when the collector is run), which would result in `x_ptr` dangling!

Trait Implementations

impl<T: Trace + ?Sized> AsRef<T> for Gc<T>

fn as_ref(&self) -> &T

Performs the conversion.

impl<T: Trace + ?Sized> Borrow<T> for Gc<T>

fn borrow(&self) -> &T

Immutably borrows from an owned value.

impl<T: Trace + ?Sized> Clone for Gc<T>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Trace + ?Sized + Debug> Debug for Gc<T>

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

Formats the value using the given formatter.

impl<T: Trace + Default> Default for Gc<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: Trace + ?Sized> Deref for Gc<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<T: Trace + ?Sized + Display> Display for Gc<T>

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

Formats the value using the given formatter.

impl<T: Trace + ?Sized> Drop for Gc<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T: Trace + ?Sized> Finalize for Gc<T>

fn finalize(&self)

impl<T: Trace> From<T> for Gc<T>

fn from(t: T) -> Self

Performs the conversion.

impl<T: Trace + ?Sized + Hash> Hash for Gc<T>

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<T: Trace + ?Sized + Ord> Ord for Gc<T>

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl<T: Trace + ?Sized + PartialEq> PartialEq<Gc<T>> for Gc<T>

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<T: Trace + ?Sized + PartialOrd> PartialOrd<Gc<T>> for Gc<T>

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Self) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Self) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Self) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Self) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: Trace + ?Sized> Pointer for Gc<T>

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

Formats the value using the given formatter.

impl<T: Trace + ?Sized> Trace for Gc<T>

unsafe fn trace(&self)

Marks all contained Gcs.

unsafe fn root(&self)

Increments the root-count of all contained Gcs.

unsafe fn unroot(&self)

Decrements the root-count of all contained Gcs.

fn finalize_glue(&self)

Runs Finalize::finalize() on this object and all contained subobjects

impl<T: Trace + ?Sized + Eq> Eq for Gc<T>