Swift 5.4 Released

Ted Kremenek from Apple's Swift Core Team just dropped Swift 5.4, and it's packed with performance wins that'll make your builds faster and your runtime leaner. This isn't just new syntax—it's measurable speed improvements across the board.

Swift 5.4 brings significant language enhancements including result builders and extended implicit member syntax, but the real story is under the hood. The release delivers faster protocol conformance checks, smarter incremental builds, and 4x faster code completion in large codebases. Windows developers also get full Swift Package Manager support for the first time.

Key Takeaways

• Code completion 4x faster in large functions (20ms to 5ms)
• Protocol conformance checks significantly faster with improved hash table caching
• Incremental builds now track dependencies at member level, not file level
• Swift Package Manager now works on Windows with per-user dependency caching
• Type checker handles complex expressions that previously timed out

The compiler's new approach to tracking dependencies could dramatically change how you structure your Swift projects for optimal build times.