SE-0453: Vector, a fixed size array

Evolution Proposal Reviews
27

With the linked macOS toolchain, I'm unable to use an explicit numeric type parameter.

The inferred parameter works with literals

var v3i: Vector<_, Int> = [0, 1, 2]

But any explicit numeric type parameter fails, blocking tests for the closure initializer:

var v3i = Vector<3, Int> { $0 }

Errors:

  • On number: Expected '>' to end generic argument clause
  • At top of file: New Swift parser generated errors for code that C++ parser accepted

Am I missing some experimental/upcoming feature flag?

Would building the toolchain without assertions unblock this error?

Thanks in advance -

Configuration details
  • macOS toolchain: (org.swift.pr.76438.1604)
  • macOS 15.1 on Apple silicon
  • Xcode 16.0 (16A242d) (but same result from command-line with SPM)
  • Package.swift settings
    • Swift language mode: 6
    • SwiftSettings: .unsafeFlags(["-Xfrontend", "-disable-availability-checking"])
      • (to avoid availability error wrt macOS 9999)