Struct alloc_compose::FallbackAlloc

pub struct FallbackAlloc<Primary, Fallback> {
    pub primary: Primary,
    pub fallback: Fallback,
}

An allocator equivalent of an "or" operator in algebra.

An allocation request is first attempted with the Primary allocator. If that fails, the request is forwarded to the Fallback allocator. All other requests are dispatched appropriately to one of the two allocators.

A FallbackAlloc is useful for fast, special-purpose allocators backed up by general-purpose allocators like Global or System.

Fields

primary: Primary

The primary allocator

fallback: Fallback

The fallback allocator

Trait Implementations

impl<Primary, Fallback> AllocRef for FallbackAlloc<Primary, Fallback> where
    Primary: AllocRef + Owns,
    Fallback: AllocRef, 

fn alloc(self, layout: Layout, init: AllocInit) -> Result<MemoryBlock, AllocErr>

On success, returns a memory block meeting the size and alignment guarantees of layout.

unsafe fn dealloc(self, memory: MemoryBlock)

Deallocates the memory denoted by memory.

unsafe fn grow(
    self,
    memory: &mut MemoryBlock,
    new_size: usize,
    placement: ReallocPlacement,
    init: AllocInit
) -> Result<(), AllocErr>

Attempts to extend the memory block.

unsafe fn shrink(
    self,
    memory: &mut MemoryBlock,
    new_size: usize,
    placement: ReallocPlacement
) -> Result<(), AllocErr>

Attempts to shrink the memory block.

impl<Primary: Clone, Fallback: Clone> Clone for FallbackAlloc<Primary, Fallback>

fn clone(&self) -> FallbackAlloc<Primary, Fallback>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<Primary: Copy, Fallback: Copy> Copy for FallbackAlloc<Primary, Fallback>

impl<Primary: Debug, Fallback: Debug> Debug for FallbackAlloc<Primary, Fallback>

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

Formats the value using the given formatter.

impl<Primary, Fallback> Owns for FallbackAlloc<Primary, Fallback> where
    Primary: Owns,
    Fallback: Owns, 

fn owns(&self, memory: &MemoryBlock) -> bool

Returns if the allocator owns the passed MemoryBlock.