updated to version 0.16.0
see installed CHANGELOG.md
## 0.16.0 2022-10-08


### Added

- Support for custom config classes via `config_class:` option (#136 by @solnic)

```ruby
extend Dry::Configurable(config_class: MyConfig)
```

Your config class should inherit from `Dry::Configurable::Config`.
- Return `Dry::Core::Constants::Undefined` (instead of nil) as the value for non-configured settings via a `default_undefined: true` option (#141 by @timriley)

```ruby
extend Dry::Configurable(default_undefined: true)
```

You must opt into this feature via the `default_undefined: true` option. Non-configured setting values are still `nil` by default.

### Fixed

- Remove exec bit from version.rb (#139 by @Fryguy)

### Changed

- Improve memory usage by separating setting definitions from config values (#138 by @timriley)

Your usage of dry-configurable may be impacted if you have been accessing objects from `_settings` or the internals of `Dry::Configurable::Config`. `_settings` now returns `Dry::Configurable::Setting` instances, which contain only the details from the setting's definition. Setting _values_ remain in `Dry::Configurable::Config`.
- Use Zeitwerk to speed up load time (#135 by @solnic)

[Compare v0.15.0...v0.16.0](https://github.com/dry-rb/dry-configurable/compare/v0.15.0...v0.16.0)