[go-nuts] unreachable elements in slice and garbage collection

I don't think that the elements between the length and capacity of a
slice can be considered garbage. The slice is defined as pointing
into an underlying array, and the length of that array is the capacity
of the slice. Since you are permitted to change the length of the
slice to any value up to the capacity, that implies that any element
of the underlying array is still accessible by the program. Those
elements can not be collected.

The elements before the start of the slice, on the other hand, could
be collected, if the garbage collector can prove that no slice points
to them. The garbage collector does not currently implement that, and
I doubt that it would be profitable.

Ian

I'd nil it. The object is stored in the underlying array, the array holds a
reference so it wouldn't be collected until the array was abandoned.

Example: http://play.golang.org/p/lNIdbDHIyD

Example: http://play.golang.org/p/_WfkqioNJS