Struct growable::Growable

pub struct Growable { /* fields omitted */ }

A chunk of the heap memory that can be assigned with an arbitrary type.

Examples

First, let's spawn a new Growable. In this case no allocation will be performed.

  let growable = Growable::new();

Now we can assign some data to it.

  let arr: Reusable<[char; 3]> = growable.consume(['f', 'o', 'o']);
  assert_eq!(&*arr, &['f', 'o', 'o']);

No longer wanted data can be then freed on demand, fetching Growable back. Then it might be assigned with some data again and so on.

  let growable = Reusable::free(arr);
  let arr: Reusable<[char; 6]> = growable.consume(['f', 'o', 'o', 'b', 'a', 'r']);
  assert_eq!(&*arr, &['f', 'o', 'o', 'b', 'a', 'r']);

Methods

impl Growable

pub fn new() -> Self

Returns a new instance of Growable but does not allocate any memory on the heap yet.

Examples

  let _ = Growable::new();

pub fn with_capacity_for_type<T>() -> Self

Returns a new instance of Growable with memory already allocated on the heap suitable to store an instance of a given type T.

Examples

  struct Foo {
      a: u8,
      b: usize,
      c: (),
  }
  let _ = Growable::with_capacity_for_type::<Foo>();

pub fn with_capacity(len: usize, ptr_alignment: usize) -> Self

Returns a new instance of Growable with memory already allocated on the heap.

Panics

• ptr_alignment is not a power of two.
• len overflows after being rounded up to the nearest multiple of the alignment.

Examples

  let _ = Growable::with_capacity(256, 16);

pub fn is_empty(&self) -> bool

Returns true if no memory has been allocated yet.

pub fn len(&self) -> usize

Returns the amount of memory allocated by this Growable.

pub fn alignment(&self) -> usize

Returns the alignment.

pub fn consume<T>(self, t: T) -> Reusable<T>

Places an instance of T on the heap, an actual (re)allocation will be performed only if there is not enough space or the pointer alignment is invalid.

Notes

Might trigger oom() handler.

Examples

  let growable = Growable::with_capacity(128, 8);
  let num = growable.consume(0usize);
  assert_eq!(*num, 0usize);

Trait Implementations

impl Send for Growable

impl Sync for Growable

impl Clone for Growable

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Pointer for Growable

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

Formats the value using the given formatter.

impl Debug for Growable

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

Formats the value using the given formatter.

impl Default for Growable

fn default() -> Self

Returns the "default value" for a type.

impl Drop for Growable

fn drop(&mut self)

Executes the destructor for this type.