## [Unreleased]
### Changed
- `System w a` is now a synonym for `SystemT w IO a`.
  A variable monad argument allows apecs to be run in monads like ST or STM.
  Most of the library has been rewritten to be as permissive as possible in its monad argument.

## [0.4.1.2]
### Changed
- Either can now be deleted, deleting `Either a b` is the same as deleting `(a,b)`.
- Some were missing their inline pragma's, now they don't

## [0.4.1.1]
### Changed
- Export `Get`, `Set`, `Destroy`, `Members` by default
- Export `cfold`, `cfoldM`, `cfoldM_` by default
- Fix () instance

## [0.4.1.0]
### Added
- `cfold`, `cfoldM`, `cfoldM_`
- `Either` instances and `EitherStore`

### Changed
- Changed MaybeStore implementation to no longer use -1 for missing entities.
- Fixed some outdated documentation.
- Change the `global` void entity to -2, just to be sure it won't conflict if accidentally used in a cache.

## [0.4.0.0]
### Added
- A changelog

### Changed
- `Store` is now split into 5 separate type classes; `ExplInit`, `ExplGet`, `ExplSet`, `ExplDestroy`, and `ExplMembers`.
    This makes it illegal to e.g. iterate over a `Not`.
- phantom arguments are now given as `Proxy` values, re-exported from `Data.Proxy`. This makes phantom arguments explicit and avoids undefined values.