Question

Possible Duplicate:
Adding a tuple to a set does not work

I have this code:

class A

var buffer = Buffer[(A, Int)]()

then, somewhere:

val a = new A
buffer += (a, 0) // error

the type inferencer fails on a in (a, 0) telling that I pass A when I must pass (A, Int):

scala> def make {
     | val a = new A
     | buffer += (a, 0)
     | }
<console>:11: error: type mismatch;
 found   : A
 required: (A, Int)
       buffer += (a, 0)
              ^

however if I do this:

val a = new A
val tuple = (a, 0)
buffer += tuple

the error is gone. Is this some kind of bug or am I missing something?

Answer 1

The compiler does not know, whether you mean buffer.+=(a,0) or buffer += Tuple2(a,0) here.

possible solutions:

buffer += Tuple2(a, 0)

buffer += Pair(a, 0) // Pair is an alias for Tuple2

buffer += ((a, 0))

buffer += a -> 0