# What's changed?
* Fix up the `std::iterator_traits` definitions for some Luau data
structures.
* Replace some of the usages of `std::unordered_set` and
`std::unordered_map` with Luau-provided data structures to increase
performance and reduce overall number of heap allocations.
* Update some of the documentation links in comments throughout the
codebase to correctly point to the moved repository.
* Expanded JSON encoder for AST to support singleton types.
* Fixed a bug in `luau-analyze` where exceptions in the last module
being checked during multithreaded analysis would not be rethrown.
### New type solver
* Introduce a `refine` type family to handle deferred refinements during
type inference, replacing the old `RefineConstraint`.
* Continued work on the implementation of type states, fixing some known
bugs/blockers.
* Added support for variadic functions in new non-strict mode, enabling
broader support for builtins and the Roblox API.
### Internal Contributors
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
---------
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>