Apple Releases Swift 6.4, Boosting WebAssembly Speeds by Up to 40x
Updated
Updated · InfoWorld · Sep 23
Apple Releases Swift 6.4, Boosting WebAssembly Speeds by Up to 40x
1 articles · Updated · InfoWorld · Sep 23
Summary
Swift 6.4 broadens Apple’s language across apps, servers, embedded devices and browsers, with upgrades to core APIs, builds, debugging, interoperability and runtime performance.
Swift Build is now the default in Swift Package Manager, giving Linux, macOS and Windows projects a more consistent build path, while Subprocess 1.0 adds a stable cross-platform way to run other programs.
WebAssembly bridging through JavaScript kit runs up to 40 times faster, and interoperability expands with Swift Span bridging to C++20 std::span plus wider async and callback support in Swift/Java interop.
LLDB now imports modules through precise dependency tracking, completing a multi-release debug-info overhaul that significantly shrinks Linux and Windows debug builds and Darwin dSYM bundles.
Embedded Swift also gains existential types and richer error handling, while new array types and the Iterable protocol aim to cut unnecessary copies without sacrificing memory safety.