Function try_new_uninit_box

crates/core/src/error/boxed.rs:28–43

()

/// Create a `Box<T>`, or return an `OutOfMemory` error.
#[inline]
pub(crate) fn try_new_uninit_box<T>() -> Result<Box<MaybeUninit<T>>, OutOfMemory> {
    let layout = std_alloc::alloc::Layout::new::<MaybeUninit<T>>();

    if layout.size() == 0 {
        // NB: no actual allocation takes place when boxing zero-sized types.
        return Ok(Box::new(MaybeUninit::uninit()));
    }

    // Safety: layout size is non-zero.
    let ptr = unsafe { try_alloc(layout)? };

    let ptr = ptr.cast::<MaybeUninit<T>>();

    // Safety: The pointer's memory block was allocated by the global allocator.
    Ok(unsafe { Box::from_raw(ptr.as_ptr()) })
}