erroneous error: "to pass 'x' as ...interface { }, use 'x...'"

[rogpeppe]

the following program fails to compile, with the error:
"to pass 'x' as ...interface { }, use 'x...'" although
it is valid according to the specification.

this applies also in the case where other
arguments follow x, which is less likely to be a mistake.

package main
import "fmt"
func main() { f(1,2,4) }
func f(x ...int) { fmt.Printf("[%v]\n", x) }

71a9509287b2+ tip

[griesemer]

Comment 1:

Here is a self-contained package (no imports) showing the same problem:
package P
func f(x ...int) { g(x) }
func g(x ...interface{}){}
test.go:2: to pass 'x' as ...interface { }, use 'x...'
test.go:2: cannot use x (type []int) as type []interface { } in function argument
(both 6g and gccgo show an error). This may be a left-over error message to ease
transition to the  new rules.

Labels changed: added compilerbug.

Owner changed to [email protected].

Status changed to Accepted.

[rsc]

Comment 2:

You can work around this with interface{}(x).
I am reluctant to remove the error, even though
it is incorrect.

[rogpeppe]

Comment 3:

i think it's ok if the error remains for the final argument case,
but where there are additional arguments like this:
var n int
func f(x ...int) { fmt.Printf("[%v] %d\n", x, n) }
i think it's less reasonable.
it was in that context i first encountered this error.

[gopherbot]

Comment 4 by robert.hencke:

This seems to have been fixed in http://code.google.com/p/go/source/detail?r=e17a171b737b

[rsc]

Comment 5:

Status changed to Fixed.