Commits
Austin Zheng committed 6231cca6092
[stdlib] Implementing O(1) methods on `CountableClosedRange` (#2993) * [stdlib] Implementing O(1) methods on `CountableClosedRange` Changes: - Implemented O(1) `index(_:offsetBy:)` and `distance(from:to:)` methods on `CountableClosedRange` - Fixed some unit tests - Added many more unit tests for Countable*Range index APIs * Clarify test intent