### New features

* [#276](https://github.com/rubocop/rubocop-performance/pull/276): Add new `Performance/StringIdentifierArgument` cop. ([@koic][])
* [#204](https://github.com/rubocop/rubocop-performance/issues/204): Add `Performance/Sum` option to ignore potential false positives. ([@leoarnold][])
* [#269](https://github.com/rubocop/rubocop-performance/pull/269): Add `#to_d` support to `BigDecimalWithNumericArgument`. ([@leoarnold][])

### Bug fixes

* [#277](https://github.com/rubocop/rubocop-performance/pull/277): Fix an incorrect autocorrect for `Performance/MapCompact` when using `map.compact.first` and there is a line break after `map.compact` and receiver. ([@koic][])
* [#273](https://github.com/rubocop/rubocop-performance/pull/273): Fix an incorrect autocorrect for `Performance/RedundantStringChars` when using `str.chars[0]`. ([@koic][])

### Changes

* [#270](https://github.com/rubocop/rubocop-performance/pull/270): Mark `Performance/Sum` auto-correction as unsafe and extend documentation. ([@leoarnold][])
* [#274](https://github.com/rubocop/rubocop-performance/pull/274): Unmark `AutoCorrect: false` from `Performance/CaseWhenSplat`. ([@koic][])
* [#275](https://github.com/rubocop/rubocop-performance/pull/275): Unmark `AutoCorrect: false` from `Performance/TimesMap`. ([@koic][])

[@koic]: https://github.com/koic
[@leoarnold]: https://github.com/leoarnold
