Struct ptr_union::Union2

pub struct Union2<A, B> { /* fields omitted */ }

A pointer union of two pointer types.

This is a tagged union of two pointer types such as Box<T>, Arc<T>, or &T that is only as big as a pointer. This is accomplished by storing the tag in the alignment bits of the pointer.

As such, the pointer must be aligned to at least u16 (#[repr(align(2))]). This is enforced through the use of UnionBuilder.

Methods

impl<A: ErasablePtr, B: ErasablePtr> Union2<A, B>

pub fn is_a(&self) -> bool

Check if the union is this variant.

pub fn into_a(self) -> Result<A, Self>

Extract this variant from the union.

Returns the union on error.

pub fn with_a<R>(&self, f: impl FnOnce(&A) -> R) -> Option<R>

Run a closure with this variant.

pub fn a(&self) -> Option<&A::Target> where
    A: Deref, 

Get a reference to this variant's target.

pub fn clone_a(&self) -> Option<A> where
    A: Clone, 

Clone this variant out of the union.

pub fn copy_a(&self) -> Option<A> where
    A: Copy, 

Copy this variant out of the union.

pub fn is_b(&self) -> bool

Check if the union is this variant.

pub fn into_b(self) -> Result<B, Self>

Extract this variant from the union.

Returns the union on error.

pub fn with_b<R>(&self, f: impl FnOnce(&B) -> R) -> Option<R>

Run a closure with this variant.

pub fn b(&self) -> Option<&B::Target> where
    B: Deref, 

Get a reference to this variant's target.

pub fn clone_b(&self) -> Option<B> where
    B: Clone, 

Clone this variant out of the union.

pub fn copy_b(&self) -> Option<B> where
    B: Copy, 

Copy this variant out of the union.

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

Check if two Unions are the same variant and point to the same value (not that the values compare as equal).

pub fn as_deref<'a>(
    &'a self,
    proof: UnionBuilder<Union2<&'a A::Target, &'a B::Target>>
) -> Union2<&'a A::Target, &'a B::Target> where
    A: Deref,
    B: Deref,
    &'a A::Target: ErasablePtr,
    &'a B::Target: ErasablePtr, 

Dereference the current pointer.

impl<A: ErasablePtr, B: ErasablePtr> Union2<A, B>

pub unsafe fn as_deref_unchecked<'a>(
    &'a self
) -> Union2<&'a A::Target, &'a B::Target> where
    A: Deref,
    B: Deref,
    &'a A::Target: ErasablePtr,
    &'a B::Target: ErasablePtr, 

Dereference the current pointer.

Safety

The reference produced by dereferencing must align to at least u16 (2 bytes).

pub fn unpack(self) -> Enum2<A, B>

Unpack this union into an enum.

Trait Implementations

impl<A: ErasablePtr, B: ErasablePtr> Clone for Union2<A, B> where
    A: Clone,
    B: Clone, 

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<A: ErasablePtr, B: ErasablePtr> Copy for Union2<A, B> where
    A: Copy,
    B: Copy, 

impl<A: ErasablePtr, B: ErasablePtr> Debug for Union2<A, B> where
    A: Debug,
    B: Debug, 

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

Formats the value using the given formatter.

impl<A: ErasablePtr, B: ErasablePtr> Eq for Union2<A, B> where
    A: Eq,
    B: Eq, 

impl<A: ErasablePtr, B: ErasablePtr> ErasablePtr for Union2<A, B>

fn erase(this: Self) -> ErasedPtr

Turn this erasable pointer into an erased pointer.

unsafe fn unerase(this: ErasedPtr) -> Self

Unerase this erased pointer.

impl<A: ErasablePtr, B: ErasablePtr> Hash for Union2<A, B> where
    A: Hash,
    B: Hash, 

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

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<A: ErasablePtr, B: ErasablePtr> PartialEq<Union2<A, B>> for Union2<A, B> where
    A: PartialEq,
    B: PartialEq, 

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

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

#[must_use]fn ne(&self, other: &Rhs) -> bool

This method tests for !=.