SE-0439 trailing commas allowed in tuples but not tuple types

[stephencelis]

Description

Tuple type expressions seemed to have been left out, which is an unfortunate thing to have to special case when transforming Swift syntax for macros.

Reproduction

// ✅
let t1 = (
  1,
  2,
  3,
)

let t2: (
  Int,
  Int,
  Int,
) = (  // 🛑 Unexpected ',' separator
  1,
  2,
  3,
)

Expected behavior

I'd expect both to compile.

Environment

Apple Swift version 6.2-dev (LLVM 9ae4b59a6edd27c, Swift 9b6c04e)
Target: arm64-apple-macosx15.0
Build config: +assertions

Additional information

No response

[stephencelis]

/cc @mateusrodriguesxyz

[hamishknight]

This was recently fixed by #81612 (6.2: #81653)