Struct OutOfMemory 

pub struct OutOfMemory { /* private fields */ }

Out-of-memory error.

This error is the sentinel for allocation failure due to memory exhaustion.

Constructing an Error from an OutOfMemory does not allocate.

Allocation failure inside any Error method that must allocate (e.g. Error::context) will propagate an OutOfMemory error.

Implementations

impl OutOfMemory

pub const fn new(requested_allocation_size: usize) -> OutOfMemory

Construct a new OutOfMemory error.

The requested_allocation_size argument should be the size (in bytes) of the associated allocation that was attempted and failed.

This operation does not allocate.

Example

use alloc::alloc::{Layout, alloc};
use core::ptr::NonNull;

/// Attempt to allocate a block of memory from the global allocator,
/// returning an `OutOfMemory` error on failure.
fn try_global_alloc(layout: Layout) -> Result<NonNull<u8>, OutOfMemory> {
    if layout.size() == 0 {
        return Ok(NonNull::dangling());
    }

    // Safety: the layout's size is non-zero.
    let ptr = unsafe { alloc(layout) };

    if let Some(ptr) = NonNull::new(ptr) {
        Ok(ptr)
    } else {
        // The allocation failed, so return an `OutOfMemory` error,
        // passing the attempted allocation's size into the `OutOfMemory`
        // constructor.
        Err(OutOfMemory::new(layout.size()))
    }
}

pub fn requested_allocation_size(&self) -> usize

Get the size (in bytes) of the associated allocation that was attempted and which failed.

Very large allocation sizes (near isize::MAX and larger) may be capped to a maximum value.

Example

let oom = OutOfMemory::new(8192);
assert_eq!(oom.requested_allocation_size(), 8192);

Trait Implementations

impl Clone for OutOfMemory

fn clone(&self) -> OutOfMemory

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for OutOfMemory

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Display for OutOfMemory

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Error for OutOfMemory

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl Copy for OutOfMemory

impl Send for OutOfMemory

impl Sync for OutOfMemory