"Extra arguments" error when passing a parameter pack into a function that also accepts a closure argument.

[simanerush]

Description

When trying to use a function that accepts a parameter pack and a closure as its arguments, I'm getting the "extra arguments" error.

Reproduction

func test<each T>(_ pack: repeat each T, callback: (repeat each T) -> Void) {}

test(1, 2, 3, callback: { _ in })

The error:

error: extra arguments at positions #2, #3 in call
test(1, 2, 3, callback: { _ in })
    ^
note: 'test(_:callback:)' declared here
func test<each T>(_ pack: repeat each T, callback: (repeat each T) -> Void) {
     ^

Expected behavior

The above code should compile because 1, 2, 3 is a valid parameter pack, and should be used as a first argument to the function.

Environment

Swift version 5.11-dev (LLVM d50917983d84235, Swift 98e65d0)

Additional information

The following code, with (repeat each T) replaced with (Int) in the type of the closure, works fine:

func test<each T>(_ pack: repeat each T, callback: (Int) -> Void) {}

test(1, 2, 3, callback: { _ in })

[hborla]

I think this is a misleading error message. The real issue is the closure doesn't have enough arguments. This builds fine

func test<each T>(_ pack: repeat each T, callback: (repeat each T) -> Void) {}

test(1, 2, 3, callback: { _, _, _ in })

[simanerush]

Ah, I totally missed that. Thank you Holly!