Struct ngen::arena::TempArena

pub struct TempArena { /* fields omitted */ }

A temporary memory arena.

Implementations

impl TempArena

pub fn with_capacity(capacity: usize) -> Result<Self, String>

Creates a temporary memory arena with a given capacity, returning an error if it is unable to allocate the full amount of memory.

Example

let arena = TempArena::with_capacity(1024).unwrap();

pub fn len(&self) -> usize

Returns the total amount of memory used since the last reset.

Example

let mut arena = TempArena::with_capacity(1024).unwrap();
arena.push(4.0f32);
assert_eq!(arena.len(), std::mem::size_of::<f32>());

pub fn push_default<'a, T: Default>(&'a self) -> &'a mut T

Pushes a default value for a given T into the temp arena, using the correct alignment for the pushed value.

Example

let mut arena = TempArena::with_capacity(1024).unwrap();
let forty_two = arena.push_default::<i32>();
assert_eq!(forty_two, &0);

pub fn push<'a, T>(&'a self, default: T) -> &'a mut T

Pushes a new value into the temp arena, using the correct alignment for the pushed value.

Example

let mut arena = TempArena::with_capacity(1024).unwrap();
let forty_two = arena.push(42);
assert_eq!(forty_two, &42);

pub fn reset(&mut self)

Resets the current memory arena, pointing the current location to the start of the allocated memory.

Example

let mut arena = TempArena::with_capacity(1024).unwrap();

// Push some items into the arena.
for i in 0..42 {
    arena.push(i);
}

assert_eq!(arena.len(), std::mem::size_of::<i32>() * 42);
arena.reset();
assert_eq!(arena.len(), 0);

pub fn array<T>(&mut self) -> Array<'_, T>

Returns exclusive access to the memory arena to create a contiguous, and growable, array of items.

Example

let mut arena = TempArena::with_capacity(1024).unwrap();

let mut array = arena.array();
array.push(42);