Struct triomphe::ThinArc

#[repr(transparent)]pub struct ThinArc<H, T> { /* fields omitted */ }

A "thin" Arc containing dynamically sized data

This is functionally equivalent to Arc<(H, [T])>

When you create an Arc containing a dynamically sized type like HeaderSlice<H, [T]>, the Arc is represented on the stack as a "fat pointer", where the length of the slice is stored alongside the Arc's pointer. In some situations you may wish to have a thin pointer instead, perhaps for FFI compatibility or space efficiency.

Note that we use [T; 0] in order to have the right alignment for T.

ThinArc solves this by storing the length in the allocation itself, via HeaderSliceWithLength.

Implementations

impl<H, T> ThinArc<H, T>

pub fn with_arc<F, U>(&self, f: F) -> U where
    F: FnOnce(&Arc<HeaderSlice<HeaderWithLength<H>, [T]>>) -> U, 

Temporarily converts |self| into a bonafide Arc and exposes it to the provided callback. The refcount is not modified.

pub fn from_header_and_iter<I>(header: H, items: I) -> Self where
    I: Iterator<Item = T> + ExactSizeIterator, 

Creates a ThinArc for a HeaderSlice using the given header struct and iterator to generate the slice.

pub fn ptr(&self) -> *const c_void

Returns the address on the heap of the ThinArc itself -- not the T within it -- for memory reporting.

pub fn heap_ptr(&self) -> *const c_void

Returns the address on the heap of the Arc itself -- not the T within it -- for memory reporting.

Trait Implementations

impl<H, T> Clone for ThinArc<H, T>

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<H, T> Deref for ThinArc<H, T>

type Target = HeaderSlice<HeaderWithLength<H>, [T]>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<H, T> Drop for ThinArc<H, T>

fn drop(&mut self)

Executes the destructor for this type.

impl<H: Eq, T: Eq> Eq for ThinArc<H, T>

impl<H: Hash, T: Hash> Hash for ThinArc<H, T>

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

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<H: PartialEq, T: PartialEq> PartialEq<ThinArc<H, T>> for ThinArc<H, T>

fn eq(&self, other: &ThinArc<H, T>) -> 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 !=.

impl<H: Sync + Send, T: Sync + Send> Send for ThinArc<H, T>

impl<H: Sync + Send, T: Sync + Send> Sync for ThinArc<H, T>