An attempt to collect several proposals of rust-lang/wg-allocators into a MVP.
Alloc traitThe first thing to notice is, that [Alloc] was renamed to [AllocRef] in order to show that they are typically
implemented for a reference or smart pointer or ZST, not directly for the type that actually holds the allocator’s
state.
Issue: rust-lang/wg-allocators#8
[AllocRef] was split up into [AllocRef], [DeallocRef], and [ReallocRef] to make more flexible allocators
possible.
Issue: rust-lang/wg-allocators#9
The allocators has to be associated with [BuildAllocRef]. It is related to the allocator traits similar how
[BuildHasher] is related to [Hasher]. Although the signatures are different, it makes an even more flexible
allocator design possible.
Issue: rust-lang/wg-allocators#12
Added an associative error type to [AllocRef]. Besides adding the possibility of returning additional information on
allocation failure, it's also possible to split the usage of the [AllocRef] into a fallible and an infallible case.
Personally I think this is a pretty big deal, as kernel programmer can rely on allocation, which will never fail. If
an allocation can fail, only a try_*_in method may be available. To maintain backwards compatibility, [AbortAlloc]
was introduced. [AbortAlloc] wraps another allocator, but aborts on OOM thus AbortAlloc<Global> may be used as
default allocator for [Box] or Vec. To realize this, [AbortAlloc] implements AllocRef<Error=!>.
Issue: rust-lang/wg-allocators#23
The new layout type [NonZeroLayout] was introduced. Currently, implementors of [Alloc] can chose to allow
zero-sized allocation so in a generic context it's impossible to rely on this, so banning zero-sized allocation is a
possible step to prevent this. This also removes unsafe from [AllocRef::alloc] and [AllocRef::alloc_zeroed], and
unlocks the possibility to move the extension API like alloc_array into a separate trait.
Issue: rust-lang/wg-allocators#16
[Box] Missing Items:
FromIterator<A> for Box<[A]> as Vec is not implemented yet.T: Copy for Fn-traits as it's not possible for downstream crates.[RawVec] (Only methods and basic traits)
Alloc-WG is distributed under the terms of both the MIT license and the Apache License (Version 2.0).
See LICENSE-APACHE and LICENSE-MIT for details.