Struct Pointer 

pub struct Pointer<T> { /* private fields */ }

A pointer to some T in the GC heap.

Safety

A Pointer<T> is a small step up in safety from a raw pointer. A valid Pointer<T> instance is a guarantee that:

• The pointer points into the GC heap, within a GC-allocated page, and not on top of the PageHeader.

• The pointer has the alignment required by the type and GC.

Note that Pointer<T> does not pin its referent like GcRef<T> does. Therefore, a Pointer<T> can still easily be made to dangle or point at uninitialized memory! The Pointer<T> type is not for general use (use GcRef<T> for that instead), only for GC internals. We have to make it pub so that #[derive(IntoHeap)] can generate code that uses it, but no one else should!

Implementations

impl<T> Pointer<T>

pub unsafe fn new(ptr: *const T) -> Pointer<T>

Construct a new Pointer<T> from a raw *const T.

Safety

It is the responsibility of callers to ensure that the guarantees mentioned above hold true.

Panics

Panics if the pointer is not aligned properly, or if it would clobber the GC’s internal PageHeader.

pub fn is_null(&self) -> bool

Is this pointer null?

pub unsafe fn as_ref(&self) -> &T

Get a reference to the pointed-to T instance.

Safety

If a GC happens and reclaims the referent while the returned reference is in use, it will result in use-after-free.

If this pointer doesn’t point at a valid T instance, then all hell will break loose.

Panics

Panics if the pointer is null.

pub fn as_raw(&self) -> *const T

Get the underlying raw pointer.

pub fn as_void(&self) -> *const ()

Get the underlying raw pointer as a *const ().

pub fn as_usize(&self) -> usize

Get the underlying raw pointer as a usize.

Trait Implementations

impl<T> Clone for Pointer<T>

fn clone(&self) -> Pointer<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> Debug for Pointer<T>

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

Formats the value using the given formatter.

impl<T> From<Pointer<T>> for UntypedPointer

fn from(p: Pointer<T>) -> UntypedPointer

Converts to this type from the input type.

impl<T> From<Pointer<T>> for usize

fn from(p: Pointer<T>) -> usize

Converts to this type from the input type.

impl<T: Hash> Hash for Pointer<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, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: Ord> Ord for Pointer<T>

fn cmp(&self, other: &Pointer<T>) -> Ordering

This method returns an Ordering between self and other.

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

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

where Self: Sized,

Restrict a value to a certain interval.

impl<T> PartialEq for Pointer<T>

fn eq(&self, other: &Pointer<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: PartialOrd> PartialOrd for Pointer<T>

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl<T> Copy for Pointer<T>

impl<T> Eq for Pointer<T>