Update to nightly 2022-02-08

Fixes

• Support nightly version 2022-02-08
  • Requires specifying some more explicit types to assist GAT inference.

Some API improvements (still needs redesign)

Significant API changes, but the API still needs a redesign to fix soundness issues.

To be clear, this does not fix the outstanding soundness issues.

See commit notes for full list of changes.

Major Features

• Add GcError wrapper
• Add GcString as garbage collected string
• Add an "epsilon" collector that never collects memory
• Implement GcDeserialize using serde
• Optionally emulate core::alloc API
• Add GcIndexMap collection

Public API Changes

• Parameterize GcSafe by 'gc lifetime and CollectorId
• Make GcErase trait an alias GcRebrand

Internal Improvements & Fixes

• Use const generics for arrays
• Fix trait_object_trace! macro
• Make GcHandle use generic associated types
• Handle cycles in Trace::NEEDS_TRACE
• Remove #[feature(...)]s that have been stabilized

Add GcSimpleAlloc::alloc_uninit method

Features

• Add GcSimpleAlloc::alloc_uninit method
• Support tracing parking_lot::{Mutex, RwLock}
• Use thin pointers

Internal Changes

• Simplify unsafe_gc_impl! using proc-macro-kwargs
• [simple] Expose a method to get a GcType

Add support for arrays, vectors, and trait objects

Major Changes

• Add support for garbage collected arrays/vectors (#16)
• Implement support for tracing trait objects (#15)
• Revert "Make GcRef a trait once again"
• Move NEEDS_DROP to Trace trait

Minor Fixes

• Fix duplicate 'Id' generics with #[zerogc(mutable)]
• Implement Trace for RefCell/Cell iff T: NullTrace
• Implement GcSimpleAlloc for DummyContext

Make GcRef a trait once again

• [simple] Move collector ids in the object header
  • When using multiple collectors, this reduces the pointer size from 128 -> 64 bits\
• Use compare_exchange instead of CAS for global collector

There are some serious API changes that will be coming up soon here.

Significantly cleanup zerogc_derive

• e225f32: Mark binary_trees_parallel::Tree with collector_id(SimpleCollectorId)
• b337b2f: Add procedural unsafe_gc_impl! macro for manual impls (#22)
  • This siginificantly simplifies the implementation for stdlib types
• Implement NullTrace for PhantomData
• 010be99: Add unsafe attribute to skip generating destructor
• aee5449: Make #[zerogc(nop_trace) implicitly skip the Drop impl
• bbb8d0b: Add #[derive(NullTrace)] as sugar for #[zerogc(nop_trace)]
• ab5fcbb: Drop parking_lot's usage of 'nightly' feature
  • NOTE: The simple collector still depends on other nightly features..

Support derive for enums and types with a single non-gc lifetime

• [BREAKING] Split GcBrand up into GcErase + GcRebrand
• [derive] Implement safety checks for GcErase + GCRebrand
• [derive] Fix parse errors in procedural derive for enums
• Implement Trace for bool and char
• Implement Trace for &'static str
• Support deriving erase/rebrand for non-gc lifetimes where Self: NullTrace
  • There can be one and only one lifetime, and it can't be 'gc

The API should be (starting to) settle down towards the v0.2.0 release. The v0.2.0 release will include a Generational GC, support for non-sized types, and builtin supports for arrays. It will be the first release that is not marked as a "pre-release",

[derive] Support ignoring lifetimes on Trace

We only bumped the version on zerogc-derive

Use traits to control if collectors are singletons or thread safe

Now the zerogc-context crate can support singleton and multi-instance collectors in the same compilation. Likewise, it can also support thread-safe and thread-unsafe collectors in the same compilation. The simple implementation is still controlled by cfg-features but this is a step in the right direction.

• Implement Trace and GcSafe for String
  • I cant believe I missed this -_-
• [derive] Support ignoring parameters for #[derive(Trace)]
• [derive] Support deriving NullTrace via #[zerogc(nop_trace)] attribute

Separate 'context' crate from 'simple' implementation

This will allow multiple collector implementations to share code around the context management and maintaining shadow stacks.