1 //! Low-level allocation and OOM-handling utilities. 2 3 mod arc; 4 mod boxed; 5 mod try_new; 6 mod vec; 7 8 pub use boxed::{ 9 BoxedSliceFromFallibleIterError, TooFewItemsOrOom, boxed_slice_write_iter, 10 new_boxed_slice_from_fallible_iter, new_boxed_slice_from_iter, 11 new_boxed_slice_from_iter_with_len, new_uninit_boxed_slice, 12 }; 13 pub use try_new::{TryNew, try_new}; 14 pub use vec::Vec; 15 16 use crate::error::OutOfMemory; 17 use core::{alloc::Layout, ptr::NonNull}; 18 19 /// Try to allocate a block of memory that fits the given layout, or return an 20 /// `OutOfMemory` error. 21 /// 22 /// # Safety 23 /// 24 /// Same as `alloc::alloc::alloc`: layout must have non-zero size. 25 #[inline] 26 unsafe fn try_alloc(layout: Layout) -> Result<NonNull<u8>, OutOfMemory> { 27 // Safety: same as our safety conditions. 28 debug_assert!(layout.size() > 0); 29 let ptr = unsafe { std_alloc::alloc::alloc(layout) }; 30 31 if let Some(ptr) = NonNull::new(ptr) { 32 Ok(ptr) 33 } else { 34 Err(OutOfMemory::new(layout.size())) 35 } 36 } 37